CN1961499B - Space-time transmit diversity systems and methods for OFDM applications - Google Patents

Abstract

Embodiments of the invention provide orthogonal Frequency Division Multiplexing-Space-Time Block Codes (OFDMSTBC) mappings for code rate 1, 2 and 4 codes for 4 Transmit Antennas. To overcome the innate weakness of known codes, a new class of STBC codes is provided which is particularly suited for OFDM applications, although other applications are also contemplated. Codes for STBC mappings in the time direction, the frequency direction and a combined time frequency mapping for multiple antennas are provided. In OFDM applications, these codes exploit the properties of OFDM and FEC codes to substantially maintain the advantages of Alamouti codes. Furthermore, while the detailed examples given herein focus on four antenna applications, they can be easily extended to systems with more than four antennas.

Description

Be used for space-time transmit diversity systems and method that OFDM is used

Related application

The application requires the rights and interests of the U.S. Provisional Patent Application No.60/563802 that submits in the U.S. Provisional Patent Application No.60/558566 that submitted on April 2nd, 2004, on April 21st, 2004 and the U.S. Provisional Patent Application No.60/566009 that submitted on April 28th, 2004.

Technical field

The present invention relates to space-time transmit diversity systems and method for OFDM (OFDM) application.

Background technology

For the open loop fading channel, often consider diversity, unique selection is to alleviate influence of fading and improved system reliability.Although FEC (forward error correction) coding provides important time diversity, for the slow fading environment, space diversity/polarization proves more efficiently.The target of so-called space time code is that to make diversity gain be maximum.

Basically there are two kinds of space time codes: grid code and block code.Although the grid code provides additional coding gain, but they have following shortcoming: decoder more complicated (because these codes operate qam symbol), and be difficult to that grid space time code is broadcast code with powerful soft decoding FEC code, Ru Te and convolution code is connected in series.The space time block code (STBC) do not provide coding gain, but they are easy to the decoding orthogonal design code of complexity (particularly for), and they can be combined with other soft decoding FEC code naturally.Exactly because these reasons, STBC (space time block code) is more practical and extensively adopted by numerous standards.

Foremost STBC code is by Alamouti and Tarokh (US 6185258) invention, and wherein code matrices is as shown in table 1 below.

Table 1-Alamouti code

	Time t	Time (t+T)
			Antenna 1	s 1	s 2
Antenna 2	-s 2 *	s 1 *

This code has several attributes, and making it is desirable for space diversity.Signal is quadrature; Thereby realize full-diversity at receiver side.Transmitting power between two antennas (and two time slots) through overbalance; Thereby can adopt low-cost power amplifier, this reduces again the modulator-demodulator cost.Its code check is 1; Therefore do not damage throughput.Its maximum likelihood decoder is very simple, and this makes the cost of best decoder very little.

Yet, there is not this class orthogonal code in proof for having the system that surpasses two transmitter antennas after a while.Therefore, focus is transferred to following two zones: design has the quadrature STBC code less than 1 code check; And design accurate quadrature STBC code in order to keep the attribute of code check 1.Although first method infringement throughput of system, second method are lost because of orthogonality and are damaged signal quality.

Have some code variants to belong to above classification, wherein focus is in other zone, and for example power-balance and code check are processed; But there is no to find to have the code of desirable Alamouti.

Following table 2 is for the first example of the STBC code of 4 transmitting antennas (code A).This is the orthogonal code with code check 3/4.This code makes great efforts to keep the orthogonality of code, keeps thus diversity rank and signal quality.

Table 2-code check 3/4 orthogonal code (code A)

	Time t	Time (t+T)	Time (t+2T)	Time (t+3T)
					Antenna 1	s 1	-s 2 *	-s 3 *	x
Antenna 2	s 2	s 1 *	x	s 3 *
					Antenna 3	s 3	x	s 1 *	-s 2 *
Antenna 4	x	-s 3	s 2	s 1

Adopt this code, each received signal has 4 diversity rank.But a shortcoming of this code is its code check loss, and this must compensate in the FEC code.In other words, due to the code check loss of STBC, the code check of FEC must be higher.This may cause the problem of those powerful grid codes of higher code check, and its coding gain is lost in when fluctuation becomes excessive and becomes obvious.Note, this code is not obtained the total power balance on transmitting antenna.Existence can overcome other available code of this shortcoming.

Table 3 comprises for the second example of the STBC code of 4 antenna applications (code B).This is code check 1 non-orthogonal code.This code is made great efforts the throughput of keeping system, thus can the loss coding gain in the FEC level.

Table 3-code check 1 non-orthogonal code (code B)

	Time t	Time (t+T)	Time (t+2T)	Time (t+3T)
					Antenna 1	s 1	-s 2 *	s 3	-s 4 *
Antenna 2	s 2	s 1 *	s 4	s 3 *
					Antenna 3	s 3	-s 4 *	s 1	-s 2 *
Antenna 4	s 4	s 3 *	s 2	s 1 *

Because code B is no longer orthogonal code, so its determinant is subject to the phase mutual interference.Equivalent channel matrix Q is defined as

$Q=\left[\begin{array}{cccc}{h}_1& h_2& h_3& h_4\\ {\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">h</figure-callout>}}_2^{*}& -h_1^{*}& h_4^{*}& -h_3^{*}\\ h_3& h_4& h_1& h_2\\ h_4^{*}& -h_3^{*}& h_2^{*}& -h_1^{*}\end{array}\right]---\left(1\right)$

{。##.##1},

r＝Qs (2)

Wherein

And s=[s ₁s ₂s ₃s ₄] ^TThe determinant of Q is given by following formula

|Q|＝A ²-B ²

(3)

A=|h wherein ₁| ²+ | h ₂| ²+ | h ₃| ²+ | h ₄| ², and B=2 (Re (h ₁h ₃ ^*)+Re (h ₂h ₄)).Element B ²Expression is lost caused loss because of orthogonality.Due to B ²〉=0, therefore be unfavorable for all the time the code performance.

Summary of the invention

According to an aspect of the present invention, it is the method for one space time block code that a kind of 2n of being used to (n＞=2) antennamitter mapping code check is provided, the method comprises, by n to continuous transmission intercal in respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make at n and use all antennas in to continuous transmission intercal, and only having a pair of antenna is movable in given transmission intercal, transmits 2n transmission symbol.

according to another aspect of the present invention, it is the method for one space time block code that a kind of 2n of being used to (n＞=2) antennamitter mapping code check is provided, the method comprises by transmitting 2n transmission symbol on a plurality of subcarriers of following steps in the OFDM frequency spectrum of each subcarrier carry out to(for) each transmission intercal: at n on each of adjacent OFDM subcarrier, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make and use all subcarriers, and only having a pair of antenna is movable for given subcarrier in given transmission intercal.

According to another aspect of the present invention, the method of a kind of 2n of being used to (n＞=2) antennamitter mapping space time block code is provided, the method comprises, by in two continuous transmission intercals, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, transmit 2n transmission symbol.

According to another aspect of the present invention, the method of a kind of 2n of being used to (n＞=2) antennamitter mapping space time block code is provided, the method comprises by following steps and transmits 2n transmission symbol: for each transmission intercal, on a pair of adjacent OFDM subcarrier, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols.

According to another aspect of the present invention, the method of a kind of 2n+1 of being used to (n＞=1) antennamitter mapping space time block code is provided, the method comprises by following steps and transmits transmission symbol: k to continuous transmission intercal in, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make at k using all antennas at least one of continuous transmission intercal, and use at least one transmitting antenna at k in two of continuous transmission intercal.

According to another aspect of the present invention, the method of a kind of 2n+1 of being used to (n＞=1) antennamitter mapping space time block code is provided, the method is suitable for transmitting transmission symbol, its mode is: for each transmission intercal, k to subcarrier on, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make at k using all antennas at least one of continuous transmission intercal, and use at least one transmitting antenna at k in two of subcarrier.

According to another aspect of the present invention, provide a kind of method that is used to 4 antennamitter mapping space time block codes, the method comprises selects suitable rate code from the code set of available rate code, and wherein code set is:

Perhaps

According to another aspect of the present invention, provide a kind of method that is used to 4 antennamitter mapping space time block codes, the method comprises selects suitable rate code from the code set of available rate code, and wherein code set is:

Perhaps

According to another aspect of the present invention, it is the method for 3/4 space time block code that a kind of 4 antennamitters mappings code checks that are used to are provided, the method comprises, by in a pair of continuous transmission intercal, the first respective antenna on, transmit the corresponding Alamouti code block that comprises two transmission symbols on given subcarrier, and the second respective antenna on, transmit the corresponding Alamouti code block that comprises a transmission symbol on same subcarrier, make at this and use all antennas in to continuous transmission intercal, transmit 3 transmission symbols.

According to another aspect of the present invention, it is the method for one space time block code that a kind of 2n of being used to (n＞=2) antennamitter mapping code check is provided, the method comprises, by in a pair of continuous transmission intercal, respective antenna on, transmit the corresponding Alamouti code block comprise two transmission symbols on given subcarrier, make at this and use all antennas in to continuous transmission intercal, and every pair of antenna is movable on different subcarriers, transmits 2n transmission symbol.

According to another aspect of the present invention, it is the method for one space time block code that a kind of 2n of being used to (n＞=2) antennamitter mapping code check is provided, the method comprises, by in a pair of continuous transmission intercal, respective antenna on, transmit the corresponding Alamouti code block comprise n transmission symbol on given subcarrier, make this to continuous transmission intercal in all antennas of use, transmit 4n transmission symbol.

According to another aspect of the present invention, provide the method for the MIMO ofdm signal that a kind of form for transmitting with Y=HF (S) represents, wherein Y ^1xMThe output of mimo channel, H ^MxNTBe the matrix of mimo channel characteristic, F (s) expression is grouped into S ₁=[s ₁s ₂s ₃s ₄], S ₂=[s ₅s ₆s ₇s ₈] and S ₃=[s ₉s ₁₀s ₁₁s ₁₂] compound incoming symbol S=[s ₁s ₂... s _L] the space time encoder matrix, the method comprises that according to the receiver antenna quantity on the wireless terminal that be fit to receive the MIMOOFDM signal that multiple antenna transmitter sends be that described wireless terminal is selected suitable code.

By reading below in conjunction with the explanation of accompanying drawing to specific embodiment of the present invention, those skilled in the art will other side of the present invention fully aware of and feature.

Description of drawings

Describe the preferred embodiments of the present invention now with reference to accompanying drawing, accompanying drawing comprises:

The schematic diagram of 4 antennamitters that the support MIMO-OFDM that Figure 1A is with embodiment provided by the present invention is used in conjunction with communicates by letter;

The multiple antenna transmitter that the support MIMO-OFDM that Figure 1B is with embodiment provided by the present invention is used in conjunction with communicates by letter and the schematic diagram of receiver;

The schematic diagram of the another kind of multiple antenna transmitter that the support MIMO-OFDM that Fig. 1 C is with embodiment provided by the present invention is used in conjunction with communicates by letter;

The schematic diagram of another multiple antenna transmitter that the support MIMO-OFDM that Fig. 1 D is with embodiment provided by the present invention is used in conjunction with communicates by letter;

The schematic diagram of another multiple antenna transmitter that the support MIMO-OFDM that Fig. 1 E is with embodiment provided by the present invention is used in conjunction with communicates by letter;

Fig. 2 means and is being coded in the schematic diagram of the transmission of the STBC piece on a plurality of subcarriers on time orientation for space time;

Fig. 3 compares with having code mapping now, the picture specification of the improvement performance of code mapping embodiment provided by the present invention;

Fig. 4 compares with having code mapping now, the picture specification of the improvement high mobility speed ability of code mapping embodiment provided by the present invention;

Fig. 5 compares with having code mapping now, the picture specification of the improvement Hypomobility speed ability of code mapping embodiment provided by the present invention; And

Fig. 6 means and is being coded in the schematic diagram of the transmission of the STBC piece on a plurality of subcarriers on time orientation for space time.

Embodiment

According to embodiments of the invention, supplying method is used for the user is mapped to many antenna transmissions resource, makes network can utilize temporal frequency diversity and multi-user diversity.In addition, mapping also allows provided for radio resources management/distribution flexibly, and the service based on different QoS is provided.In identical frames, can support to have SISO, MISO, the user of MIMO ability.

As general introduction, it may be on different OFDM resources such as the subchannel of AMC subchannel and/or diversity subchannel etc. that each user can be mapped to.For MIMO user, preferably, support a plurality of different space time encoding schemes, for example SM (spatial reuse) and STTD (Space Time Transmit Diversity).

On continuous basis, there is the OFDM symbol stream related with each transmitting antenna.At first each user may be mapped to one or more OFDM symbols, and then each OFDM symbol may be mapped to its related antenna.In certain embodiments, this mapping also allows to be performed by the speed control (PARC) of antenna.

Each OFDM symbol can be mapped to its related antenna in the subcarrier territory.For some subcarrier, if do not shine upon specific user's data, may be fed into corresponding antenna to the zero allocation of this subcarrier.

The utmost point simplified example that particular moment in time may transmit due to specific OFDM symbol and antenna mapping is as shown in Figure 1A.Figure 1A illustrates four antenna transmission systems, and it is used for transmitting six user grouping 60,62,64,66,68,70 in described example, and wherein each is through FEC (forward error correction) and modulation.Six users' of particular moment the concrete mapping of six groupings is described.Along with passage of time, the mode of number of users and/or mapping user grouping preferably dynamically changes.

For particular moment, distribute the OFDM bandwidth in four different frequency bands F1, F2, F3, F4.They for example may be considered to the AMC subchannel.Similarly method can be used for the diversity subchannel.

Each grouping will adopt selected mapping scheme to be mapped to four antennas.The below describes various space time mapping schemes in detail.In certain embodiments, multiple different scheme is available, perhaps gives transmitting antenna and the reception antenna of determined number.For example, for 2 * 2 systems, preferably can select STTD or SM (BLAST-Bell Laboratory sheaf space time).In other embodiments, only realize single alternative for each antenna alignment.The single antenna user adopts single-input single-output (SISO) (it may comprise PARC-and control by the speed of antenna) transmission plan.

Adopt unique antenna 1 to transmit the first grouping 60 on frequency band F3, this expression 1 * 1SISO transmission.

The second grouping 62 transmits on two antennas 1 and 2 in frequency band F4, this expression 2 * 1,2 * 2 or 2 * 4MIMO transmission.

The 3rd grouping 64 only transmits on antenna 2 in frequency band F3, and this represents 1 * 1SISO transmission equally.

The 4th grouping 66 transmits on frequency band F2 by antenna 3.

The 5th grouping 68 transmits on frequency band F1 by two antennas 3 and 4.

At last, grouping 70 transmits on unique frequency band F2 of antenna 4.

In general, each grouping can be mapped to respectively on part or all antenna.This makes MIMO and the non-MIMO user can be mixed, and in above example, grouping 60,64,66 and 70 is used for non-MIMO user.Grouping 62 and 64 is used for MIMO user.

The flexible mapping that note that MIMO and non-MIMO user is applicable to the context of " part is utilized " and " complete utilization ".Utilize by part, given base station is the part of the whole OFDM frequency band of Internet access only.Institute's definitional part that will belong in this case, whole frequency band for the defined sub-band F1 of the example of Figure 1A, F2, F3, F4.Utilize by part, can distribute different frequency bands to the different base station that geographically approaches.By complete utilization, whole OFDM frequency band is used in each base station.By a kind of like this realization, for the instantiation of Figure 1A, sub-band F1, F2, F3, F4 will be mapped to whole frequency band.

For SISO user, with the single band of using on single antenna.For MIMO user, allocation list is shown N _T* N _R

Flexible structure shown in as an example can be used for STTD and BLAST in Figure 1A.For example, grouping 62 can adopt the frequency band F4 on the antenna 1 and 2 that utilizes BLAST or STTD to transmit.

Instantiation shown in Figure 1A is designed to show that coexisting of SISO and MIMO is STTD and/or BLAST.The quantity of the sub-band in the OFDM frequency band and shape thereof, size, position etc. are realized specific details beyond doubt.Mapping can be carried out on every OFDM symbolic base or for a plurality of OFDM symbols.

The title of submitting on April 4th, 2005 is＜wireless communications method, system and signal structure 〉, defined the details of carrying out from the method for a plurality of antennas transmissions in applicant's common unsettled PCT number of patent application PCT/CA2005/000507, by reference it intactly is incorporated into this.The method generally comprises:

The available OFDM bandwidth of each antenna is divided into subchannel;

Define a plurality of zones, each zone is defined by the OFDM symbol of corresponding set of sub-channels and the quantity that defines;

A plurality of antennas one or more that define each regional respective antenna mapping and select to be used for this zone, antenna mapping comprises at least one MIMO mapping;

Adopt the respective antenna mapping at least one user's content map in the zone each;

Be to transmit each zone on the selected one or more antennas in zone.

The another kind of mode of considering this situation is, defined each temporal frequency piece can have its oneself matrix.In case specified matrix, defined the antenna amount of output place.For example, 2 * 2 matrixes need two antennas; 4 * 4 matrixes need four antennas.The uncertain quantity of definite different user that can shine upon uniquely of matrix.Provide instantiation in following table.

A plurality of users' content need to be shone upon in consistent and conflict free mode undoubtedly.In addition, need to notify each user about its content with the position/time that is transmitted.

For each individual consumer, antenna mapping is realized STTD, SM and PARC transmission for AMC subchannel or diversity subchannel.In one embodiment, any of six different mappings configurations can be applicable to each individual consumer, comprising three 4 transmitting antenna mappings, 2 transmitting antenna mappings and single antenna mapping.

Up link can comprise for example two kinds of patterns: (1) has the STTD of two transmitting antenna ability SS, and (2) have the virtual MIMO of single transmit antenna capabilities SS.

Referring now to Figure 1B, 1C, 1D and 1E, shown is concrete transmitter configuration.In a preferred embodiment, transmitter is dynamically reconfigurable, in order to realize the transmission that employing respective transmissions form carries out to a plurality of users.The instantiation of following Figure 1B, 1C, 1D and 1E can be considered to " snapshot " of this reconfigurable transmitter.These configurations also can exist simultaneously for the different sub-bands of the whole OFDM frequency band that adopts.For example, the configuration of Figure 1B can be used for the first set of sub-channels or OFDM frequency band and an associated user; The configuration of Fig. 1 C can be used for the second set of sub-channels or the 2nd OFDM frequency band and associated user, etc.Certainly, it is repetition physically that the many assemblies that are expressed as repetition need not.For example, single IFFT and related radiating circuit can use by antenna, wherein carry out different mappings, and then are input to the suitable subcarrier of IFFT.

Figure 1B illustrates an example arrangement, wherein has according to single inlet flow to carry out the matrix of STTD coding and have level code for two, three or four transmitting antennas.Then inlet flow 1000 carries out the STC coding through coding and modulation in space time encoder 1002, wherein have two, three or four outputs, and they are fed to corresponding emission chain and are transmitted.Corresponding receiver structure generally is expressed as 1004.In this case, according to the receiver ability, with undefined matrix F _4x1Or F _4x2Can be used for four transmitting antennas, perhaps with undefined F _2x1Can be used for two transmitting antennas.These are all adoptable STTD matrixes for example; Other matrix is feasible.

Fig. 1 C illustrates an example arrangement, wherein has for a plurality of inlet flows to carry out the matrix of STTD coding and have level code for two, three or four transmitting antennas.Inlet flow 1006,1008 (only illustrates two, more inlet flows are feasible) through coding and modulation, then carry out the STC coding in space time encoder 1010, encoder has two, three or four outputs, and they are fed to corresponding emission chain and are sent out.In this case, according to the receiver ability, with undefined matrix F _4x1Or F _4x2Can be used for four transmitting antennas, perhaps with undefined F _2x1Can be used for two transmitting antennas.These are all adoptable STTD matrixes for example; Other matrix is feasible.

Fig. 1 D illustrates an example arrangement, wherein has SM (for example BLAST) coding of matrix carry out to(for) single inlet flow.Inlet flow 1012 is through coding and modulation, and then demultiplexing is two, three or four streams 1012,1014, and they are fed to corresponding emission chain and are sent out.In this case, matrix F _4x4May be used for four transmitting antennas, perhaps F _2x2,2x4Can be used for two transmitting antennas, they are defined following, and they both are adoptable SM matrixes for example; Other matrix is feasible.The example that this is so-called " vertical coding ", therein, the incoming symbol of given inlet flow is vertical distribution (being that the time is simultaneously upper) between a plurality of antennas.

Fig. 1 E illustrates an example arrangement, wherein has SM (for example BLAST) coding of matrix carry out to(for) a plurality of inlet flows.Inlet flow 1020,1022 (only illustrate two, more inlet flow is feasible) process coding and modulation, and be fed to corresponding emission chain and send.In this case, matrix F _4x4May be used for four transmitting antennas, perhaps F _2x2,2x4Can be used for two transmitting antennas, they are defined following, and they both are adoptable SM matrixes for example; Other matrix is feasible.This be so-called example of " level code ", therein, the incoming symbol horizontal distribution of given inlet flow (namely in time in order) is on single antenna.

Concrete antenna mapping example

Describe now distribute based on time encoding flexible modes between the quasi-orthogonal space of above-described SISO, STTD and SM one more specifically example in detail.

(BS) upper down link open-loop transmission of a plurality of antennas that adopts can configure by some transmission modes in the base station.Suppose N _TThe quantity of the transmitting antenna on BS, and N _RBe the quantity of the reception antenna on terminal use's platform (SS), the MIMO allocation list is shown N _TxN _RNote, for the SISO transmission, only use in the available transmission antenna.Can adopt any existing SISO code structure.

Index	1	2	3	4	5
						FEC	R＝1/5	R＝1/3	R＝1/2	R＝2/3	R＝4/5
Modulation	QPSK	16QAM	64QAM

For the MIMO downlink transmission, preferably adopt the space time coding.In one embodiment, female code that time transmit diversity between 4 * 4 quasi-orthogonal spaces (QOSTTD) code is encoded as space time, and can bore a hole in time, in order to be optimized for different reception antennas configurations.The MIMO sending and receiving can be by Y=HF (S) expression, wherein, and Y ^1xMThe output of mimo channel, H ^MxNTTBe the matrix of mimo channel characteristic, F (s) expression is grouped into S ₁=[s ₁s ₂s ₃s ₄], S ₂=[s ₅s ₆s ₇s ₈] and S ₃=[s ₉s ₁₀s ₁₁s ₁₂] compound incoming symbol S=[s ₁s ₂... s _L] the space time encoder matrix, and the row of encoder matrix F (s) is that stand-alone antenna sends output.

The code that is fit to 4 * 1 configurations is: (STC code check=1)

$F_{4x1}({\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_2,S_3)=\left[\begin{array}{cccccccccccc}{s}_1& -{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_2}^{*}& -{{\mathrm{<figure-callout\; id="3"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_3}^{*}& s_4& s_5& -{s_7}^{*}& -{s_8}^{*}& s_6& s_9& -{s_{12}}^{*}& -{s_{10}}^{*}& s_{11}\\ s_2& {{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_1}^{*}& -{{\mathrm{<figure-callout\; id="4"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_4}^{*}& -s_3& s_6& {s_8}^{*}& {s_7}^{*}& s_5& s_{10}& -{s_{11}}^{*}& {s_9}^{*}& -s_{12}\\ s_3& -{{\mathrm{<figure-callout\; id="4"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_4}^{*}& {{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_1}^{*}& -s_2& s_7& {{\mathrm{<figure-callout\; id="5"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_5}^{*}& -{{\mathrm{<figure-callout\; id="6"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_6}^{*}& -s_8& s_{11}& {s_{10}}^{*}& {s_{12}}^{*}& s_9\\ s_4& {{\mathrm{<figure-callout\; id="3"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_3}^{*}& {{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_2}^{*}& s_1& s_8& -{{\mathrm{<figure-callout\; id="6"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_6}^{*}& {{\mathrm{<figure-callout\; id="5"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_5}^{*}& -s_7& s_{12}& {s_9}^{*}& -{s_{11}}^{*}& -s_{10}\end{array}\right]$

The codes of suitable 4 * 2 configurations (STC code check=2, STTD), to F _4x1(S ₁, S ₂, S ₃) row 3﹠amp; 4,7﹠amp; 8 and 11﹠amp; 12 carry out the time perforation, draw:

$F_{4x2}({\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_2,S_3)=\left[\begin{array}{cccccc}{s}_1& -{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_2}^{*}& s_5& -{s_7}^{*}& s_9& -{s_{12}}^{*}\\ s_2& {{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_1}^{*}& s_6& {s_8}^{*}& s_{10}& -{s_{11}}^{*}\\ s_3& -{{\mathrm{<figure-callout\; id="4"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_4}^{*}& s_7& {{\mathrm{<figure-callout\; id="5"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_5}^{*}& s_{11}& {s_{10}}^{*}\\ s_4& {{\mathrm{<figure-callout\; id="3"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_3}^{*}& s_8& -{{\mathrm{<figure-callout\; id="6"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_6}^{*}& s_{12}& {s_9}^{*}\end{array}\right]$

The code (STC code check=4, spatial reuse) that is fit to 4 * 4 configurations is preferably to F _4x2(S ₁, S ₂, S ₃) row 1,3 and 5 bore a hole, draw:

$F_{4x4}({\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_2,S_3)=\left[\begin{array}{ccc}{s}_1& s_5& s_9\\ s_2& s_6& s_{10}\\ s_3& s_7& s_{11}\\ s_4& s_8& s_{12}\end{array}\right]$

In four system of transmit antennas, SS preferably be configured to the space time coding that different reception antenna abilities with respect to the SS class receive 4x1,4x2 or 4x4 configuration (more than the F that provides _4x1F _4x2F _4x4Be instantiation) transmission.These three kinds of patterns can be applicable to AMC subchannel and diversity subchannel.In addition, preferably the provide support model selection of DL and UL and adaptive fast feedback channel.

For two transmitting antennas, preferably support two transmission modes: Space Time Transmit Diversity and spatial reuse.

For 2 * 1 configurations, the below is an example of code structure: (STC code check=1)

$F_{2x1}({\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,S_2)=\left[\begin{array}{cccc}{s}_1& -{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_2}^{*}& s_3& -{{\mathrm{<figure-callout\; id="4"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_4}^{*}\\ s_2& {{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_1}^{*}& s_4& {{\mathrm{<figure-callout\; id="3"\; label="s"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">s</figure-callout>}}_3}^{*}\end{array}\right],$ It is Alamouti Space Time Transmit Diversity (STTD).

Configure for 2 * 2,2 * 4: (STC code check=2), to F _2x1Even column bore a hole, draw:

$F_{2x\mathrm{2,2}x4}({\mathrm{<figure-callout\; id="1"\; label="S"\; filenames="H05817160620061129E000011.png,H05817160620061129E000051.png"\; state="\{\{state\}\}">S</figure-callout>}}_1,S_2)=\left[\begin{array}{cc}{s}_1& s_3\\ s_2& {\mathrm{<figure-callout\; id="4"\; label="s"\; filenames="H05817160620061129E000011.png"\; state="\{\{state\}\}">s</figure-callout>}}_4\end{array}\right].$ This is spatial reuse (being called again BLAST).

In a preferred embodiment, SS be configured to the space time coding that different reception antenna abilities with respect to the SS class receive 2x1,2x2 or 2x4 configuration (more than the F that provides _2x1, F _2x2,2x4Be instantiation) transmission.These two kinds of patterns can be applicable to AMC subchannel and diversity subchannel.In addition, preferably the provide support model selection of DL and UL and adaptive fast feedback channel.

The details of the example implementation of above code and fast feedback channel is found in the title submitted on April 5th, 2005 for the inventor's of " supporting the method for the MIMO transmission of OFDM in using " common unsettled U. S. application number 11/547561, by reference it intactly is incorporated into this.

The code check that the first embodiment of the present invention is provided for 4 transmitting antennas is 1 OFDM-STBC mapping.In order to overcome the defective of above two kinds of codes, a kind of class of new STBC code is provided, it is particularly suitable for OFDM and uses, but also considers other application.In OFDM used, these codes utilized the attribute of OFDM and FEC code in order to keep in fact the advantage of Alamouti code.In addition, although the detailed example that provides here focuses on four antenna applications, they can be easy to expand to the system with four above antennas.

An attribute of FEC code is their diversity effects in code block.By this knowledge, the diversity rank on each quadrature amplitude modulation (QAM) symbol can be loosened in a code block.Code check 1 quadrature STBC Code Design needs each qam symbol to realize full-diversity, even be not infeasible for the antenna amount greater than two, is also some difficulty a little.But when FEC code based on soft decoding was connected in series, this was optional when system.

Therefore, provide new STBC code, so that for each qam symbol provides second-order diverse, still realize full-diversity by means of the FEC code simultaneously.Second-order diverse represents that each qam symbol is by two independences (multipath) fading channel.An example (code C) as shown in table 4 below of new STBC code.

Table 4 OFDM-STBC code check 1 orthogonal code (code C)

(antenna skipped mode 1)

	Time t	Time (t+T)	Time (t+2T)	Time (t+3T)
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	s 2	S 1 *	0	0
					Antenna 3	0	0	s 3	-s 4 *
Antenna 4	0	0	s 4	s 3 *

In table 5A, represent the another kind arrangement of the alternative antenna skipped mode different from table 4.The antenna redirect refers to reordering of mapping, make to carry out identical coding, but is-symbol is transmitted by different antennas.For example, in the antenna skipped mode 1 shown in upper table 4, be that antenna 2 distributes s at time t ₂, distribute s at time t+T ₁ ^*, in time t+2T and t+3T zero allocation.But, in the antenna skipped mode 2 of following table 5A, be that antenna 3 distributes s at time t ₂, distribute s at time t+T ₁ ^*, and in time t+2T and t+3T zero allocation.Be appreciated that these are two examples of antenna skipped mode, but to also have other antenna skipped mode be effectively and think also be in scope of the present invention within.Table 5B represents another alternative code mapping.

Table 5A-OFDM-STBC code check 1 orthogonal code (code C)

(antenna skipped mode 2)

	Time t	Time (t+T)	Time (t+2T)	Time (t+3T)
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	0	0	s 3	-s 4 *
					Antenna 3	s 2	s 1 *	0	0
Antenna 4	0	0	s 4	s 3 *

Table 5B-OFDM-STBC code check 1 orthogonal code (code C)

(antenna skipped mode 3)

	Time t	Time (t+T)	Time (t+2T)	Time (t+3T)
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	0	0	s 3	-s 4 *
					Antenna 3	0	0	s 4	s 3 *
Antenna 4	s 2	s 1 *	0	0

In a preferred embodiment, pass in time employing a plurality of different patterns, for example above-mentioned " skipped mode 1 " and " skipped mode 2 ".Its role is to, for each group code s ₁, s ₂, s ₃, s ₃, for example be used for s ₁Antenna change in time.

For above embodiment, preferably use mapping on every OFDM subcarrier basis.

For the redirect on transmitting antenna of Alamouti code, each qam symbol has 2 diversity orders; Be applied to all STBC pieces for FEC coding, realize full-diversity rank.The STBC code check is one, and each code STBC piece is quadrature.

In order to realize unbalanced power for all transmitting antennas in time domain, can see from table 4, constantly only have two transmitters to send at each, this means, for firm power P, each power amplifier (PA) can be designed to have and many dynamic range of 3dB when adopting the power-balance code.Can adopt the attribute of OFDM here.

Different pattern optimum selections ground is used for different subcarriers, makes and realizes the overall power balance.The below further is elaborated.For above instantiation, the first sets of subcarriers can be used for emission mode 1, and the second sets of subcarriers can be used for emission mode 2 at the same time.

Ofdm signal has a plurality of subcarriers, and each subcarrier is wherein regarded flat fading channel as.Fig. 2 is the illustrative example of ofdm signal, wherein, subcarrier represents with row k, k+1, k+2, k+3..., k+ (n-3), k+ (n-2), k+ (n-1), k+n in frequency domain, and the time interval represent to go t, t+T, t+2T, t+3T in time domain, represent therein STBC piece 20.

After IFFT processed generation, for the type described in the example of above Figure 1A-E, the energy of each subcarrier superposeed in time domain, and then it amplified by corresponding power amplifier.For subcarrier k, at time t and t+T, only have antenna 1 and 2 to be used for transmission, and at the same time, for subcarrier k+1, only have antenna 3 and 4 to be used for transmission.In other words, when checking from time domain, all antennas send simultaneously, but carry out for different subcarriers.Therefore, in fact the average transmit power of each antenna is balanced.This conception of species as shown in Figure 2.

In Fig. 2, each of four symbols vertically is integrated in four transmission intercals and transmits on single subcarrier, and expression two STBC pieces 20 as defined in table 4.In the first two transmission interval t and t+T, antenna 1 and 2 sends the Alamouti piece on subcarrier k+1, and in latter two transmission interval t+2T and t+3T, antenna 3 and 4 sends the Alamouti piece.Then repeat this structure (horizontal direction in Fig. 2) for a plurality of subcarriers.

In certain embodiments, mapping code on the first sets of subcarriers has above-described mapping, and second sets of subcarriers will have the mapping opposite with described mapping, it is the position of the Alamouti piece switch in the time interval/antenna mapping shown in table 4,5A and 5B.For example, on the first subcarrier, in the first two transmission interval t and t+T, antenna 1 and 2 sends the Alamouti piece, and in latter two transmission interval t+2T and t+3T, antenna 3 and 4 sends the Alamouti piece.On the second subcarrier, in the first two transmission interval t and t+T, antenna 3 and 4 sends the Alamouti piece, and in latter two transmission interval t+2T and t+3T, antenna 1 and 2 sends the Alamouti piece.

In described example, given transmission interval centering, all odd sub-carriers k, k+2 of a pair of antenna ..., k+ (n-3), k+ (n-1) they are movable, and another all even number subcarrier k+1, k+3 to antenna ..., k+ (n-2), k+n be movable.Then, for lower a pair of transmission intercal, this is opposite.This just is mapped to single subcarrier solution a kind of mode of sets of subcarriers.

In certain embodiments, different antennas is used for different subcarriers (in frequency) in order to realize the power-balance of time domain.This is that OFDM is specific, and is that the fresh code design attracts one of actual reason that realizes.

A feature performance benefit of the SNR gain aspect of the OFDM-STBC code C that is better than the nonopiate code check 1 code B of previous described prior art that provides in certain embodiments as shown in Figure 3.

Except passing through the obtained improvement in performance of fresh code, they also have other attendant advantages.In certain embodiments, this solution is particularly suitable for OFDM configuration, but is also can be suitable for other system can accept the time at the gained unbalanced power.In certain embodiments, a kind of like this structure is best, and can be generalized to 2n transmitting antenna (it is known there is no so far other R=1 full-diversity code).This code also utilizes soft decoding FEC code to realize the full-diversity of whole FEC code block.Realize optimality from the angle of the full-diversity of the STBC code check 1 full orthogonality of each STBC code block and whole FEC code block.The verified full orthogonality of the code check 1 with each STBC code block and the optimum code that respectively transmits the full-diversity of symbol of not existing.In certain embodiments, due in OFDM uses, have now the three-dimensional (being in fact 2 dimension mappings) of mapping Alamouti structure, therefore, the time span of Alamouti mapping can reduce by changing antenna or frequency dimension.

A basic assumption that is noted that STBC is that channel does not change to next transmission from a transmission.For above-mentioned prior art code, each qam symbol is transmitted four times, and in basic assumption became more and more false ambulant situation, this may cause performance loss.Obviously, first and last transmission between elapsed time (or frequency) longer, the loss that produces is larger.The fresh code utmost point is suitable for this situation, because each qam symbol is only transmitted twice successively.

Fig. 4 and Fig. 5 explanation, the performance of the embodiment of OFDM-STBC code C are all the time than above provide better about the prior art code of the performance of the performance of high mobility speed and Hypomobility speed respectively.

Above-described code mapping is to be the example that the more conventional method of one space time block code produces by being used to 2n (n＞=2) antennamitter mapping code check.By respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make at n and use all antennas in to continuous transmission intercal, and it is movable that a pair of antenna is only arranged in given transmission intercal, transmits 2n transmission symbol at n in to continuous transmission intercal.In certain embodiments, this method is carried out on every OFDM subcarrier basis.In addition, different antenna skipped mode generally is used for adopting different patterns that transmission symbol is mapped to antenna for different transmission cycles.

The code check that is used for 4 transmitting antennas is 2 OFDM-STBC

When the space time code check is 2, there is not the full orthohormbic structure of four antenna transmission situations.But can construct inferior desirable code structure, as shown in table 6.Table 7A and table 7B provide alternative antenna redirect variant.In addition, although the detailed example that provides here focuses on four antenna applications, they can be easy to expand to the system with four above antennas.

Table 6-OFDM-STBC code check 2 orthogonal codes (code D)

(antenna skipped mode 1)

	Time t	Time (t+T)
			Antenna 1	s 1	-s 2 *
Antenna 2	s 2	s 1 *
			Antenna 3	s 3	-s 4 *
Antenna 4	s 4	s 3 *

Table 7A-OFDM-STBC code check 2 orthogonal codes (code D)

(antenna skipped mode 2)

Time t

Time (t+T)

Antenna 1	s 1	-s 3 *
			Antenna 2	s 2	-s 4 *
Antenna 3	s 3	s 1 *
			Antenna 4	s 4	s 2 *

Table 7B-OFDM-STBC code check 2 orthogonal codes (code D)

(antenna skipped mode 3)

	Time t	Time (t+T)
			Antenna 1	s 1	-s 4 *
Antenna 2	s 2	-s 3 *
			Antenna 3	s 3	s 2 *
Antenna 4	s 4	s 1 *

Above-described code mapping is the example that is produced by the more conventional method for the space time block code that shines upon 2n (n＞=2) antennamitter.By respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, transmit 2n transmission symbol in two continuous transmission intercals.

Three code checks 2 " skipped mode " code can make up to form code set by various different modes.

Expansion to the frequency direction mapping

Above STBC code constructs provides by the form of mapping Alamouti structure on time orientation, and still, a kind of like this configuration also can be mapped to frequency direction.

Similar to the mapping on time orientation, an example of the power-balance configuration of the mapping on frequency direction as shown in Figure 6.In Fig. 6, subcarrier in frequency domain with row k, k+1, k+2, k+3 ..., k+ (n-3), k+ (n-2), k+ (n-1), k+n represent, and the time interval represent to go t, t+T, t+2T, t+3T in time domain, represent therein STBC piece 30.In the first two subcarrier k and k+1, antenna 1 and 2 transmits the Alamouti piece at time interval t, and in latter two subcarrier k+2 and k+3, antenna 3 and 4 transmits the Alamouti piece.Then repeat this structure (vertical direction in Fig. 6) for the follow-up time interval.In described example, given subcarrier on, odd number time interval t, t+2T ..., in t+ (n-1) T, a pair of antenna is movable, and even number time interval t+T, t+3T ..., in t+mT, another is movable to antenna.Then, for lower a pair of subcarrier, this is opposite.This just is mapped to one of many modes of sets of subcarriers to single subcarrier solution.

Example at the STBC code of mapping Alamouti structure on frequency direction is listed in table 8, table 9A and table 9B for code check 1, and lists in table 10 and table 11 for code check 2.

In addition, although the detailed example that provides here focuses on four antenna applications, they can be easy to expand to the system with four above antennas.

Table 8-OFDM-STBC code check 1 orthogonal code

(antenna skipped mode 1)

	Subcarrier k	Subcarrier k+1	Subcarrier k+2	Subcarrier k+3
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	s 2	s 1 *	0	0
					Antenna 3	0	0	s 3	-s 4 *
Antenna 4	0	0	s 4	s 3 *

Table 9A-OFDM-STBC code check 1 orthogonal code

(antenna skipped mode 2)

	Subcarrier k	Subcarrier k+1	Subcarrier k+2	Subcarrier k+3
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	0	0	s 3	-s 4 *
					Antenna 3	s 2	s 1 *	0	0
Antenna 4	0	0	s 4	s 3 *

Table 9B-OFDM-STBC code check 1 orthogonal code

(antenna skipped mode 3)

	Subcarrier k	Subcarrier k+1	Subcarrier k+2	Subcarrier k+3
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	0	0	s 3	-s 4 *
					Antenna 3	0	0	s 4	s 3 *
Antenna 4	s 2	s 1 *	0	0

Above-described code mapping is to be the example that the more conventional method of one space time block code produces by being used to 2n (n＞=2) antennamitter mapping code check.By respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, it is movable making all subcarriers of use and only having a pair of antenna for given subcarrier in given transmission intercal, at n on each of adjacent OFDM subcarrier, for each transmission intercal, transmit 2n transmission symbol on each subcarrier of a plurality of subcarriers in the OFDM frequency spectrum.In certain embodiments, in given transmission interval, subcarrier is in pairs movable, transmitting antenna between alternately.In addition, different antenna skipped mode generally is used for adopting different patterns that transmission symbol is mapped to antenna for different subcarriers.

Table 10-OFDM-STBC code check 2 orthogonal codes

(antenna skipped mode 1)

	Subcarrier k	Subcarrier k+1
			Antenna 1	s 1	-s 2 *
Antenna 2	s 2	s 1 *
			Antenna 3	s 3	-s 4 *
Antenna 4	s 4	s 3 *

Table 11A-OFDM-STBC code check 2 orthogonal codes

(antenna skipped mode 2)

	Subcarrier k	Subcarrier k+1
			Antenna 1	s 1	-s 3 *
Antenna 2	s 2	-s 4 *
			Antenna 3	s 3	s 1 *
Antenna 4	s 4	s 2 *

Table 11B-OFDM-STBC code check 2 orthogonal codes

(antenna skipped mode 3)

	Subcarrier k	Subcarrier k+1
			Antenna 1	s 1	-s 4 *
Antenna 2	s 2	-s 3 *
			Antenna 3	s 3	s 2 *
Antenna 4	s 4	s 1 *

Above-described code mapping is the example that is produced by the more conventional method that is used to 2n (n＞=2) antennamitter mapping space time block code.By respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, for each transmission intercal, transmit 2n transmission symbol on a pair of adjacent OFDM subcarrier.

Expansion to 3 transmitting antennas

Fresh code also can expand to the transmitting antenna of odd number.Table 12 and table 13 are respectively at the embodiment of the transmitting antenna OFDM-STBC code on time orientation and on frequency direction for the example with three antennas.In these embodiments, code check is reduced to 2/3, but obtains full orthogonality.

Table 12-OFDM-STBC code check 2/3 orthogonal code

(antenna skipped mode 1)

	Time t	Time (t+T)	Time (t+2T)	Time (t+3T)
					Antenna 1	s 1	-s 2 *	0	0

Antenna 2	s 2	s 1 *	s 3	-s 4 *
					Antenna 3	0	0	s 4	s 3 *

Table 13-OFDM-STBC code check 2/3 orthogonal code

(antenna skipped mode 2)

	Subcarrier k	Subcarrier k+1	Subcarrier k+2	Subcarrier k+3
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	s 2	s 1 *	s 3	-s 4 *
					Antenna 3	0	0	S 4	s 3 *

The code check that is used for 4 transmitting antennas is 4 OFDM-STBC

It is multiplexing that code check 4 configurations become the typical parallel spatial that is called BLAST.In table 14 and table 15, list in time and the embodiment of the mapping of 4 transmitting antenna BLAST on frequency.In addition, although the detailed example that provides here focuses on four antenna applications, they can be easy to expand to the system with four above antennas.

Table 14-OFDM-STBC code check 4 orthogonal codes

	Time t	Time (t+T)
			Antenna 1	s 1	s 5
Antenna 2	s 2	s 6
			Antenna 3	s 3	s 7
Antenna 4	s 4	s 8

Table 15-OFDM-STBC code check 4 orthogonal codes

	Subcarrier k	Subcarrier k+1
			Antenna 1	s 1	s 5
Antenna 2	s 2	s 6
			Antenna 3	s 3	s 7

Antenna 4

s 4

s 8

OFDM-STBC code set and antenna redirect

The various embodiment of 4 antenna transmission ODFM-STBC code sets list in table 16A, 16B and 16C.

Table 16A-code set code check 1

Table 16B-code set code check 2

Table 16C-code set code check 4

Table 16A, 16B and 16C are the embodiment of the code set of the space time mapping on time orientation.Similarly, the space time mapping also can represent on frequency direction, as shown in table 16D, 16E and 16F.

Table 16D-code set code check 1

Table 16E-code set code check 2

Table 16F-code set code check 4

Adopted specific Alamouti coding in example.Be appreciated that and adopt any code with Alamouti structure.

Decoder complexity

Compare with the prior art code, the decoder complexity that is used for the 4 emission STBC of code C is listed at table 17.Can see, the complexity of OFDM-STBC code C is less 16 times than prior art code.

Table 17-complexity relatively

Be used for the space time frequency mapping of a plurality of transmitting antennas

As mentioned above, the space time coding can be mapped to time orientation or frequency direction.In other embodiments, provide mapping, it utilizes time and frequency map, and whole antenna transmission is provided on each subcarrier according to code format simultaneously.The advantage of this assembly time frequency map comprises makes the temporal frequency span for minimum, so that within guaranteeing that space time code span is in coherence time and coincidence frequency scope.Particularly provide following instance for 4 transmitting antennas, but be appreciated that the space time frequency mapping method can carry out vague generalization for the system of the transmitting antenna with varying number.

Table 18-OFDM-space time frequency BC code check 3/4

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	-s 2 *	-s 3 *	x
Antenna 2	s 2	s 1 *	x	s 3 *
					Antenna 3	s 3	x	s 1 *	-s 2 *
Antenna 4	x	-s 3	s 2	s 1

Table 19-OFDM-space time frequency BC code check 1

(antenna skipped mode 1)

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	s 2	s 1 *	0	0
					Antenna 3	0	0	s 3	-s 4 *

Antenna 4

0

0

s 4

s 3 *

Table 20-OFDM-space time frequency BC code check 1

(antenna skipped mode 2)

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	0	0	s 3	-s 4 *
					Antenna 3	0	0	s 4	s 3 *
Antenna 4	s 2	s 1 *	0	0

Table 21-OFDM-space time frequency BC code check 1

(antenna skipped mode 3)

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	-s 2 *	0	0
Antenna 2	0	0	S 3	-s 4 *
					Antenna 3	s 2	s 1 *	0	0
Antenna 4	0	0	s 4	s 3 *

Table 22-OFDM-space time frequency BC code check 2

(antenna skipped mode 1)

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	-s 2 *	s 5	-s 7 *
Antenna 2	s 2	s 1 *	s 6	-s 8 *
					Antenna 3	s 3	-s 4 *	s 7	s 5 *
Antenna 4	s 4	s 3 *	s 8	s 6 *

Table 23-OFDM-space time frequency BC code check 2

(antenna skipped mode 2)

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	-s 2 *	s 5	-s 7 *
Antenna 2	s 2	s 1 *	s 7	s 5 *
					Antenna 3	s 3	-s 4 *	s 6	-s 8 *
Antenna 4	s 4	s 3 *	s 8	s 6 *

Table 24-OFDM-space time frequency BC code check 4

	Time t subcarrier k	Time t+T subcarrier k	Time t subcarrier k+1	Time t+T subcarrier k+1
					Antenna 1	s 1	s 5	s 9	s 13
Antenna 2	s 2	s 6	s 10	s 14
					Antenna 3	s 3	s 7	s 11	s 15
Antenna 4	s 4	s 8	s 12	s 16

According to above theory, a large amount of modifications and changes of the present invention are feasible.Therefore, should be appreciated that within the scope of the appended claims, can be not according to this paper illustrate to implement the present invention.

Claims (40)

1. One kind to be used to 2n antennamitter mapping code check be the method for one space time block code, n＞=2 wherein, described method comprises by following steps and transmits 2n transmission symbol:

   Adopt at least two different modes that 2n transmission symbol is mapped to the 2n antenna for different transmission cycles;

   N to continuous transmission intercal in, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, makes at described n and use all antennas in to continuous transmission intercal, and a pair of antenna is only arranged in given transmission intercal is movable.
2. 2. the method for claim 1, is characterized in that, described mapping realizes 2 diversity orders to each transmission symbol, and described method is carried out the FEC coding before also being included in described mapping, makes between described FEC coding and described mapping full-diversity is provided.
3. 3. the method for claim 1, is characterized in that, is applied to the OFDM transmitter on every OFDM subcarrier basis.
4. 4. method as claimed in claim 3, is characterized in that, also comprises:

   Adopt at least two different modes that transmission symbol is mapped to antenna for different transmission cycles.
5. 5. the method for claim 1, is characterized in that, n=2.
6. 6. the method for claim 1, is characterized in that, described be mapped as one of following:

   

   

   Perhaps
7. 7. method as claimed in claim 3, is characterized in that, by the Alamouti piece is mapped to subcarrier, makes in given transmission intercal, and each antenna has the active subcarriers of similar amt in fact, realizes power-balance.
8. 8. method as claimed in claim 7, is characterized in that, in every pair of transmission intercal, for the first sets of subcarriers, adopts the first mapping, and for the second sets of subcarriers, adopt second mapping opposite with that the first mapping.
9. 9. method as claimed in claim 8, is characterized in that, first be mapped as one of following:

   Perhaps
10. 10. method as claimed in claim 8, is characterized in that, the first sets of subcarriers is odd sub-carriers or even number subcarrier, and the second sets of subcarriers is residual subcarrier.
11. 11. method as claimed in claim 3 is characterized in that, each transmission intercal of the mobile radio of given subcarrier changes.
12. 12. one kind is used to 2n antennamitter mapping code check is the method for one space time block code, n＞=2 wherein, and described method comprises by following steps and transmits 2n transmission symbol on each subcarrier in a plurality of subcarriers in the OFDM frequency spectrum:

    For each transmission intercal:

    Adopt at least two different modes that 2n transmission symbol is mapped to the 2n antenna for different in described a plurality of subcarriers to movable OFDM subcarrier;

    At n on every pair of movable OFDM subcarrier, respective antenna on transmit the corresponding Alamouti code block that comprises two transmission symbols, make and use all subcarriers, and to only have a pair of antenna be movable for given subcarrier in given transmission intercal.
13. 13. method as claimed in claim 12 is characterized in that, in given transmission interval, subcarrier is in pairs movable, transmitting antenna between alternately.
14. 14. method as claimed in claim 13, it is characterized in that, have four transmitting antennas, and in given transmission interval, the even-even of subcarrier is movable on first pair of transmitting antenna, and the odd number of subcarrier is to being movable on second pair of transmitting antenna.
15. 15. method as claimed in claim 14 is characterized in that, in each transmission interval, active subcarriers antenna between the exchange.
16. 16. method as claimed in claim 14 is characterized in that, each transmission intercal of the mobile radio of given subcarrier changes.
17. 17. method as claimed in claim 12 is characterized in that, described be mapped as one of following:

    Perhaps

    
18. 18. method as claimed in claim 13 is characterized in that, for every pair of subcarrier, for first pair of time interval, adopts the first mapping, and for second pair of time interval, adopts second mapping opposite with that the first mapping.
19. 19. method as claimed in claim 18 is characterized in that, first be mapped as one of following:

    Perhaps

    
20. 20. a method that is used to 2n antennamitter mapping space time block code, n＞=2 wherein, described method comprises by following steps and transmits 2n transmission symbol:

    Adopt at least two different modes that 2n transmission symbol is mapped to the 2n antenna for different transmission cycles;

    In two continuous transmission intercals, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols.
21. 21. method as claimed in claim 20 is characterized in that, is applied to the OFDM transmitter on every OFDM subcarrier basis.
22. 22. method as claimed in claim 20 is characterized in that, described be mapped as one of following:

    Time t Time (t+T) Antenna 1 s ₁ -s ₂ ^* Antenna 2 s ₂ s ₁ ^* Antenna 3 s ₃ -s ₄ ^* Antenna 4 s ₄ s ₃ ^*

    Time t Time (t+T) Antenna 1 s ₁ -s ₃ ^* Antenna 2 s ₂ -s ₄ ^* Antenna 3 s ₃ s ₁ ^* Antenna 4 s ₄ s ₂ ^*

    Perhaps

    Time t Time (t+T) Antenna 1 s ₁ -s ₄ ^* Antenna 2 s ₂ -s ₃ ^* Antenna 3 s ₃ s ₂ ^* Antenna 4 s ₄ s ₁ ^*
23. 23. a method that is used to 2n antennamitter mapping space time block code, n＞=2 wherein, described method comprises by following steps and transmits 2n transmission symbol:

    For each transmission intercal;

    Difference for described a plurality of subcarriers adopts at least two different modes that 2n transmission symbol is mapped to the 2n antenna to movable OFDM subcarrier;

    On a pair of movable OFDM subcarrier, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols.
24. 24. method as claimed in claim 23 is characterized in that, described be mapped as one of following:

    Perhaps

    
25. 25. comprising by following steps, a method that is used to 3 antennamitter mapping space time block codes, described method transmit transmission symbol:

    In 2 pairs of continuous transmission intercals, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make and use all antennas in described 2 pairs of continuous transmission intercals, and use at least one transmitting antenna two centerings of described 2 pairs of continuous transmission intercals.
26. 26. method as claimed in claim 25 is characterized in that, is applied to OFDM and uses on every subcarrier basis.
27. 27. method as claimed in claim 25 is characterized in that, described being mapped as:
28. 28. a method that is used to 3 antennamitter mapping space time block codes, described method is adapted to pass through following steps and transmits transmission symbol:

    For each transmission intercal:

    On 2 pairs of subcarriers, respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make and use all antennas in 2 pairs of subcarrier, and use at least one transmitting antenna two centerings of described 2 pairs of subcarriers.
29. 29. method as claimed in claim 28 is characterized in that, described being mapped as:

    
30. 30. one kind is used to 2n antennamitter mapping code check is the method for one space time block code, n＞=2 wherein, and described method comprises by following steps and transmits 2n transmission symbol:

    Adopt at least two different modes that 2n transmission symbol is mapped to the 2n antenna for different active subcarriers;

    In a pair of continuous transmission intercal, on given active subcarriers respective antenna on transmit the corresponding Alamouti code block comprise two transmission symbols, make and use all antennas in described a pair of continuous transmission intercal, and every pair of antenna is movable on different subcarriers.
31. 31. method as claimed in claim 30 is characterized in that, described be mapped as one of following:

    

    Perhaps

    
32. 32. one kind is used to 2n antennamitter mapping code check is the method for one space time block code, n＞=2 wherein, and described method comprises by following steps and transmits 4n transmission symbol:

    Adopt at least two different modes that 4n transmission symbol is mapped to the 2n antenna for different active subcarriers;

    In a pair of continuous transmission intercal, on given active subcarriers respective antenna on transmit the corresponding Alamouti code block comprise n transmission symbol, make all antennas of use in described a pair of continuous transmission intercal.
33. 33. method as claimed in claim 32 is characterized in that, described be mapped as one of following:

    

    Perhaps

    
34. 34. as the described method of arbitrary claim in claims 1 to 33, it is characterized in that, also comprise the FEC code that adopts on code block, make the full-diversity of realizing whole FEC code block on receiver.
35. 35. as the described method of arbitrary claim in claims 1 to 33, it is characterized in that, every pair of antenna is spatially adjacent.
36. 36. as the described method of arbitrary claim in claims 1 to 33, it is characterized in that, every pair of antenna is spatially non-conterminous.
37. 37. one kind is disposed for carrying out the space time block code to the encoder of the mapping of a plurality of antennas, it comprises:

    At least one input, each input receives corresponding inlet flow;

    By the encode device of each inlet flow of the mapping of carrying out above arbitrary claim; And

    At least one output.
38. 38. a transmitter that is used for ofdm communication system comprises:

    At least one modulator;

    Described encoder according to claim 37; And

    A plurality of antennas.
39. 39. an ofdm communication system comprises being fit to the transmitter that enforcement of rights requires the method for arbitrary claim in 1-36.
40. 40. one kind comprises the ofdm communication system of described transmitter according to claim 38.

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