WO1992009149A1 - A radio transceiver system - Google Patents

A radio transceiver system Download PDF

Info

Publication number
WO1992009149A1
WO1992009149A1 PCT/FI1991/000340 FI9100340W WO9209149A1 WO 1992009149 A1 WO1992009149 A1 WO 1992009149A1 FI 9100340 W FI9100340 W FI 9100340W WO 9209149 A1 WO9209149 A1 WO 9209149A1
Authority
WO
WIPO (PCT)
Prior art keywords
transceiver
signal
baseband
transmitting
frequency
Prior art date
Application number
PCT/FI1991/000340
Other languages
French (fr)
Inventor
Veli Juola
Original Assignee
Telenokia Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telenokia Oy filed Critical Telenokia Oy
Priority to EP91919112A priority Critical patent/EP0511338B1/en
Priority to DE69108897T priority patent/DE69108897T2/en
Publication of WO1992009149A1 publication Critical patent/WO1992009149A1/en
Priority to NO922786A priority patent/NO300569B1/en
Priority to US07/910,125 priority patent/US5307371A/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H04B7/2643—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA]

Definitions

  • the invention relates to a radio transceiver system comprising transceiver means for transmitting an outbound signal at least at one transmitting fre ⁇ quency and for receiving an inbound signal at least at one receiving frequency, and baseband signal pro ⁇ cessing means for baseband processing of said out ⁇ bound signal before conversion up to the transmitting frequency and of said inbound signal after conversion down from the receiving frequency.
  • the object of the invention is to reduce the need for cable laying in equipment racks for digital transceivers. This is achieved by means of a radio trans ⁇ DC trans ⁇ DC transmission connection of the type disclosed in the introduction, which according to the invention is characterized in that a bidirectional serial digital transmission connection is provided between the transceiver means and the baseband signal processing means, whereby both the inbound signal from the transceiver and the outbound signal applied to the transceiver are time-division multiplexed to said bi ⁇ directional serial digital transmission connection.
  • the invention is based on the inventor's dis ⁇ covery that the same serial connection can be used both in the receiving and transmitting direction for the signalling between the radio stages and the base ⁇ band stages in transceiver systems in which the transmitting and receiving moments of the transceiver do not coincide.
  • the connection is made bidirectional by using the same connection at different times for transmitting-direction (outbound) and receiving- direction (inbound) signals. Such a bidirectional serial transmission connection reduces the need for cable laying in the equipment racks of the trans ⁇ DCver system.
  • the invention also considerably simplifies baseband switching means in systems in which frequency hopping is realized by switching baseband signals to fixed-frequency transceivers.
  • FIG. 1 shows a block diagram of a transceiver system according to the invention
  • Figure 2 shows a block diagram of the principal features of the baseband units 7a to 7c shown in Figure 1; and Figure 3 illustrates the multiplexing of the time-multiplexed serial bus 8a shown in Figure 1 into the transmitting and receiving directions.
  • the invention can be applied in any radio transceiver system but it is especially suitable for use in cellular digital mobile radio systems, such as the GSM mobile radio system, for realizing frequency hopping in radio communication between base stations and mobile radio stations (e.g. mobile telephones).
  • cellular digital mobile radio systems such as the GSM mobile radio system
  • FIG. 1 shows a block diagram of a radio transceiver system according to the invention.
  • the system comprises at least two, preferably four, radio transceiver units 6a, 6b and 6c.
  • each transceiver is full-duplex, and the duplex spacing between its receiving and transmitting RF frequencies is 45 MHz.
  • the frequency range utilized by the system is preferably from 800 to 1,000 MHz.
  • the transceivers 6a to 6c have mutually different fixed transmitting and receiving frequencies.
  • Outputs 10a to 10c in the transceivers 6a to 6c are connected to a radio-frequency combiner means 1, which combines the transmitters of the transceivers 6a to 6c to a common transmitting antenna 2 and the receivers to a common receiving antenna 3.
  • the radio-frequency combiner means 1 contains a bandpass-type transmitting filter for the transmitter of each transceiver unit 6, the filter being tuned automatically or manually to the transmitting frequency of the particular transmitter.
  • Receiving-frequency filters for each channel are located in the transceiver units 6a to 6c. In practice, the signals do not thereby propagate through the combiner means 1 in the receiving direction.
  • the combiner means 1 contains a receiving filter for the receiver of each transceiver unit 6, which filter separates from the antenna signal a signal in the band of receiving fre ⁇ quencies and then amplifies it and divides it to all the receivers.
  • the system of Figure 1 further comprises several baseband signal processing units 7a, 7b and 7c, which generate baseband modulating signals for the transceiver units 6a to 6c and which process the signals received and converted to the baseband fre- quency by the transceivers.
  • a cross-point type switching matrix 5 is provided between the trans ⁇ ceiver units 6a to 6c and the baseband signal processing units 7a to 7c. This matrix switches the baseband transmitting signals generated by the baseband signal processing units 7 to the different transceivers 6a to 6c in accordance with a pre ⁇ determined frequency-hopping sequence in such a way that the transmitting frequency of a signal generated by a certain baseband signal processing unit 7 hops from one transmitting frequency to another.
  • the switching matrix 5 switches the signals received and converted to the baseband fre ⁇ quency by the transceivers to the baseband signal processing units 7a to 7c in accordance with said predetermined frequency-hopping sequence.
  • the signal to be transmitted is a serial time- division multiplexed digital signal comprising several, preferably eight, channel time slots.
  • Figure 2 shows the principal functional blocks of the signal processing units 7a to 7c of Figure 1 for the digital signal described above.
  • the baseband processing of the signals takes place entirely in the units 7a to 7c.
  • data to be transmitted is coded and placed in a frame structure of the signal in the baseband signal processing units 7a to 7c.
  • the data is demodulated, the frame structure is disassembled, and decoding is carried out. More precisely, d ⁇ ta (e.g.
  • the chan ⁇ nel coding unit 71 may perform e.g. the following functions: adaptation of transmission rate, channel coding, interleaving, encryption, assembly of TDMA frame and adjustment of transmitter power control.
  • the unit 71 transmits a burst containing the data to be transmitted in this par ⁇ ticular time slot to an interface unit 74.
  • the inter- face 74 converts the parallel data received from the unit 71 into serial form and transmits it in serial form through the switching matrix 5 to the particular transceiver 6a to 6b, the matrix 5 switching the serial base band signal in a corresponding time slot to one of the transceivers in accordance with the frequency-hopping algorithm.
  • the interface 74 receives a serial signal from a bus 8 within each receiving time slot, the serial signal containing baseband samples derived from the signal received by a transceiver 6a to 6c selected by the switching matrix 5 in accordance with the frequency- hopping algorithm.
  • the interface 74 applies these samples in parallel form to a demodulator 73, which processes the samples.
  • the demodulator 73 contains e.g.
  • the demodulator 73 applies the demodulated data to a channel decoding unit 72, which performs e.g. the following functions: combining signals from different antennas when antenna diversity is used (two receiving antennas), disassembling the frame structure, breaking up interleaving, convolution decoding, block decoding, checking CRC and error correction, adaptation of transmission rate.
  • the channel decoding unit 72 transmits the decoded data further to the other units, and, for instance, to the base station controller of the GSM system when the transceiver system is located at the base station.
  • each transceiver 6a to 6c comprises a unit cor ⁇ responding to the serial interface unit 74 for receiving the serial signal through the switching matrix 5 from the baseband unit 7a to 7c coupled to it at each particular moment and, correspondingly, for transmitting a serial signal to the same baseband unit.
  • each baseband signal processing unit 7a to 7c has a corresponding bidirectional serial bus 8a to 8c, which connects it to a respective port in the switching matrix.
  • each transceiver 6a to 6c is connected by a separate bidirectional serial bus 9a to 9c to a respective port in the switching matrix 5.
  • a bidirectional time-division digital connection is established between each signal processing unit 7 and the particular transceiver coupled to it in accordance with the frequency-hopping algorithm through the switching matrix 5.
  • the base ⁇ band signal processing units 7a to 7c are coupled to a new transceiver after each transmission or reception of a channel time slot during the guard intervals between the channel time slots.
  • Bi ⁇ directional means that the same bus is used at dif ⁇ ferent times for both transmission-direction and reception-direction time slots.
  • a time slot complying with the GSM specification may be divided into several shorter time windows for the management of this serial bus, the windows being allocated to transmission (Tx), reception (Rx) and testing (test), as shown in Figure 3.
  • the illustrated time division of this serial connection is possible due to the fact that the transmitting and receiving moments of the GSM system do not coincide.
  • the GSM system comprises one time slot which is always transmitted at a fixed frequency (i.e. it is not included in the frequency hopping).
  • the system data of the network is transmitted to mobile telephones during this time slot.

Abstract

The invention relates to a radio transceiver system comprising transceiver means (6a to 6c) for transmitting an outbound signal at least at one transmitting frequency and for receiving an inbound signal at least at one receiving frequency, and baseband signal processing means (7a to 7c) for baseband processing of said outbound signal before conversion up to the transmitting frequency and of said received inbound signal after conversion down from the receiving frequency. To reduce cable laying in equipment racks and to simplify the realization of baseband frequency hopping, a bidirectional serial digital transmission channel is provided between the transceiver means (6a to 6c) and the baseband signal processing means (7a to 7c), whereby both the inbound signal from the transceiver and the outbound signal applied to the transceiver are time-division multiplexed to said bidirectional serial digital transmission channel.

Description

A radio transceiver system
The invention relates to a radio transceiver system comprising transceiver means for transmitting an outbound signal at least at one transmitting fre¬ quency and for receiving an inbound signal at least at one receiving frequency, and baseband signal pro¬ cessing means for baseband processing of said out¬ bound signal before conversion up to the transmitting frequency and of said inbound signal after conversion down from the receiving frequency.
The object of the invention is to reduce the need for cable laying in equipment racks for digital transceivers. This is achieved by means of a radio trans¬ ceiver system of the type disclosed in the introduction, which according to the invention is characterized in that a bidirectional serial digital transmission connection is provided between the transceiver means and the baseband signal processing means, whereby both the inbound signal from the transceiver and the outbound signal applied to the transceiver are time-division multiplexed to said bi¬ directional serial digital transmission connection. The invention is based on the inventor's dis¬ covery that the same serial connection can be used both in the receiving and transmitting direction for the signalling between the radio stages and the base¬ band stages in transceiver systems in which the transmitting and receiving moments of the transceiver do not coincide. The connection is made bidirectional by using the same connection at different times for transmitting-direction (outbound) and receiving- direction (inbound) signals. Such a bidirectional serial transmission connection reduces the need for cable laying in the equipment racks of the trans¬ ceiver system.
The invention also considerably simplifies baseband switching means in systems in which frequency hopping is realized by switching baseband signals to fixed-frequency transceivers.
The invention will now be described in greater detail by means of an illustrating embodiment with reference to the attached drawing, in which Figure 1 shows a block diagram of a transceiver system according to the invention;
Figure 2 shows a block diagram of the principal features of the baseband units 7a to 7c shown in Figure 1; and Figure 3 illustrates the multiplexing of the time-multiplexed serial bus 8a shown in Figure 1 into the transmitting and receiving directions.
The invention can be applied in any radio transceiver system but it is especially suitable for use in cellular digital mobile radio systems, such as the GSM mobile radio system, for realizing frequency hopping in radio communication between base stations and mobile radio stations (e.g. mobile telephones).
Figure 1 shows a block diagram of a radio transceiver system according to the invention. The system comprises at least two, preferably four, radio transceiver units 6a, 6b and 6c. In the GSM system, each transceiver is full-duplex, and the duplex spacing between its receiving and transmitting RF frequencies is 45 MHz. The frequency range utilized by the system is preferably from 800 to 1,000 MHz. The transceivers 6a to 6c have mutually different fixed transmitting and receiving frequencies. Outputs 10a to 10c in the transceivers 6a to 6c are connected to a radio-frequency combiner means 1, which combines the transmitters of the transceivers 6a to 6c to a common transmitting antenna 2 and the receivers to a common receiving antenna 3. Alternatively, there may be provided two receiving antennas if diversity reception is used. The radio-frequency combiner means 1 contains a bandpass-type transmitting filter for the transmitter of each transceiver unit 6, the filter being tuned automatically or manually to the transmitting frequency of the particular transmitter. Receiving-frequency filters for each channel, in turn, are located in the transceiver units 6a to 6c. In practice, the signals do not thereby propagate through the combiner means 1 in the receiving direction. Correspondingly, the combiner means 1 contains a receiving filter for the receiver of each transceiver unit 6, which filter separates from the antenna signal a signal in the band of receiving fre¬ quencies and then amplifies it and divides it to all the receivers. The system of Figure 1 further comprises several baseband signal processing units 7a, 7b and 7c, which generate baseband modulating signals for the transceiver units 6a to 6c and which process the signals received and converted to the baseband fre- quency by the transceivers. A cross-point type switching matrix 5 is provided between the trans¬ ceiver units 6a to 6c and the baseband signal processing units 7a to 7c. This matrix switches the baseband transmitting signals generated by the baseband signal processing units 7 to the different transceivers 6a to 6c in accordance with a pre¬ determined frequency-hopping sequence in such a way that the transmitting frequency of a signal generated by a certain baseband signal processing unit 7 hops from one transmitting frequency to another. Cor- respondingly, the switching matrix 5 switches the signals received and converted to the baseband fre¬ quency by the transceivers to the baseband signal processing units 7a to 7c in accordance with said predetermined frequency-hopping sequence.
In the preferred embodiment of the invention, the signal to be transmitted is a serial time- division multiplexed digital signal comprising several, preferably eight, channel time slots. Figure 2 shows the principal functional blocks of the signal processing units 7a to 7c of Figure 1 for the digital signal described above. The baseband processing of the signals takes place entirely in the units 7a to 7c. Generally speaking, data to be transmitted is coded and placed in a frame structure of the signal in the baseband signal processing units 7a to 7c. At the reception, the data is demodulated, the frame structure is disassembled, and decoding is carried out. More precisely, dόta (e.g. speech) from other parts of the radio system, such as the base station controller in the GSM system, is processed by a channel coding unit 71 before transmission. The chan¬ nel coding unit 71 may perform e.g. the following functions: adaptation of transmission rate, channel coding, interleaving, encryption, assembly of TDMA frame and adjustment of transmitter power control. Within each time slot, the unit 71 transmits a burst containing the data to be transmitted in this par¬ ticular time slot to an interface unit 74. The inter- face 74 converts the parallel data received from the unit 71 into serial form and transmits it in serial form through the switching matrix 5 to the particular transceiver 6a to 6b, the matrix 5 switching the serial base band signal in a corresponding time slot to one of the transceivers in accordance with the frequency-hopping algorithm. Correspondingly, the interface 74 receives a serial signal from a bus 8 within each receiving time slot, the serial signal containing baseband samples derived from the signal received by a transceiver 6a to 6c selected by the switching matrix 5 in accordance with the frequency- hopping algorithm. The interface 74 applies these samples in parallel form to a demodulator 73, which processes the samples. The demodulator 73 contains e.g. the following functions: sample buffering, decryption, GMSK demodulation. The demodulator 73 applies the demodulated data to a channel decoding unit 72, which performs e.g. the following functions: combining signals from different antennas when antenna diversity is used (two receiving antennas), disassembling the frame structure, breaking up interleaving, convolution decoding, block decoding, checking CRC and error correction, adaptation of transmission rate. The channel decoding unit 72 transmits the decoded data further to the other units, and, for instance, to the base station controller of the GSM system when the transceiver system is located at the base station.
In the preferred embodiment of the invention, a modulator corresponding to the demodulator 73 is provided in each transceiver 6a to 6c, in which the data to be transmitted is modulated and converted up to an appropriate radio frequency. Correspondingly, the data received at the reception is converted by the transceiver down to a baseband frequency and pre- processed for demodulation. Demodulation does not take place until in the units 7a to 7c. In addition, each transceiver 6a to 6b comprises a unit cor¬ responding to the serial interface unit 74 for receiving the serial signal through the switching matrix 5 from the baseband unit 7a to 7c coupled to it at each particular moment and, correspondingly, for transmitting a serial signal to the same baseband unit. As already mentioned above, each baseband signal processing unit 7a to 7c has a corresponding bidirectional serial bus 8a to 8c, which connects it to a respective port in the switching matrix. Similarly, each transceiver 6a to 6c is connected by a separate bidirectional serial bus 9a to 9c to a respective port in the switching matrix 5. Thus a bidirectional time-division digital connection is established between each signal processing unit 7 and the particular transceiver coupled to it in accordance with the frequency-hopping algorithm through the switching matrix 5. Preferably, the base¬ band signal processing units 7a to 7c are coupled to a new transceiver after each transmission or reception of a channel time slot during the guard intervals between the channel time slots. Bi¬ directional means that the same bus is used at dif¬ ferent times for both transmission-direction and reception-direction time slots. A time slot complying with the GSM specification may be divided into several shorter time windows for the management of this serial bus, the windows being allocated to transmission (Tx), reception (Rx) and testing (test), as shown in Figure 3. The illustrated time division of this serial connection is possible due to the fact that the transmitting and receiving moments of the GSM system do not coincide.
As to the frequency hopping, it is further to be noted that the GSM system comprises one time slot which is always transmitted at a fixed frequency (i.e. it is not included in the frequency hopping). The system data of the network is transmitted to mobile telephones during this time slot.
The attached drawings and the description related to them are only intended to illustrate the present invention. In its details, the system accord¬ ing to the invention may vary within the scope of the accompanying claims.

Claims

Claims :
1. A radio transceiver system comprising transceiver means (6a to 6c) for transmitting an outbound signal at least at one transmitting fre¬ quency and for receiving an inbound signal at least at one receiving frequency, and baseband signal pro¬ cessing means (7a to 7c) for baseband processing of said outbound signal before conversion up to the transmitting frequency and of said inbound signal after conversion down from the receiving frequency, c h a r a c t e r i z e d in that a bidirectional serial digital transmission connection is provided between the transceiver means (6a to 6c) and the baseband signal processing means (7a to 7c), whereby both the inbound signal from the transceiver and the outbound signal applied to the transceiver are time- division multiplexed to said bidirectional serial digital transmission connection.
2. A system according to claim 1, comprising transceiver means (6a to 6c) for transmitting at least one outbound digital signal at least at two transmitting frequencies varying in accordance with a predetermined frequency hopping sequence and for receiving at least one inbound digital signal at least at two receiving frequencies varying in accordance with the same sequence, c h a r a c t e r¬ i z e d in that the system comprises a fixed-frequency radio transceiver (6a to 6c) for each pair of transmitting and receiving fre¬ quencies, a baseband signal processing means (7a to 7c) for each baseband signal pair of an outbound signal and a received inbound signal, a serial interface means (74) in each transceiver and each signal processing means for transferring the received inbound baseband signal and the outbound baseband signal through said bi¬ directional serial transmission connection, and r* 5 switching means (5) for switching said baseband signal processing units (7a to 7c) in accordance with said frequency hopping sequence to said fixed-fre¬ quency transceivers (6a to 6c) for dynamically establishing said serial transmission connections. 10
3. A system according to claim 2, c h a r a c ¬ t e r i z e d in that the switching means (5) is a switching matrix.
4. A system according to any of the preceding claims, c h a r a c t e r i z e d in that said
15 serial digital signal is a time-division multiplexed signal comprising eight channel time slots.
5. A system according to claim 4, c h a r a c ¬ t e r i z e d in that the baseband signal processing means (7a to 7c) are switched after the transmission
20 or reception of each channel time slot to a different radio transceiver in accordance with said frequency hopping sequence.
6. A system according to claim 5, c h a r a c ¬ t e r i z e d in that the baseband signal processing
25 means are switched to a new transceiver preferably after the transmission or reception of each channel time slot during guard intervals between the channel time slots.
7. A transceiver system according to any of the 30 preceding claims, c h a r a c t e r i z e d in that control signals are also transmitted over said serial time-division multiplexed connection at least from
Λ the baseband means (7a to 7c) to the transceiver (6a to 6c).
PCT/FI1991/000340 1990-11-15 1991-11-14 A radio transceiver system WO1992009149A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP91919112A EP0511338B1 (en) 1990-11-15 1991-11-14 A radio transceiver system
DE69108897T DE69108897T2 (en) 1990-11-15 1991-11-14 RADIO RECEIVER SYSTEM.
NO922786A NO300569B1 (en) 1990-11-15 1992-07-14 A transmitter / receiver system
US07/910,125 US5307371A (en) 1990-11-15 1992-09-15 Radio transceiver system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI905666A FI86123C (en) 1990-11-15 1990-11-15 RADIOSAENDARMOTTAGARSYSTEM.
FI905666 1990-11-15

Publications (1)

Publication Number Publication Date
WO1992009149A1 true WO1992009149A1 (en) 1992-05-29

Family

ID=8531423

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1991/000340 WO1992009149A1 (en) 1990-11-15 1991-11-14 A radio transceiver system

Country Status (8)

Country Link
US (1) US5307371A (en)
EP (1) EP0511338B1 (en)
AT (1) ATE121244T1 (en)
AU (1) AU640542B2 (en)
DE (1) DE69108897T2 (en)
FI (1) FI86123C (en)
NO (1) NO300569B1 (en)
WO (1) WO1992009149A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1100212A1 (en) * 1999-11-09 2001-05-16 Lucent Technologies Inc. Transmitting/receiving apparatus for electromagnetic signals
GB2404527A (en) * 2003-07-26 2005-02-02 Motorola Inc Baseband processing of control signals in a multi sector base station

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2053137C (en) * 1991-10-10 2001-08-21 Rolf G. Meier Digital wireless interface
GB2313984B (en) * 1993-06-02 1998-01-28 Vtech Communications Ltd Interface protocol method and apparatus
US5430713A (en) * 1994-05-06 1995-07-04 At&T Corp. Frequency hopping in digital cellular networks
US6400966B1 (en) * 1997-10-07 2002-06-04 Telefonaktie Bolaget Lm Ericsson (Publ) Base station architecture for a mobile communications system
US7164704B1 (en) * 1999-12-09 2007-01-16 Texas Instruments Incorporated Beam forming for transmit using bluetooth modified hopping sequences (BFTBMH)
US7027424B1 (en) * 2000-05-24 2006-04-11 Vtech Communications, Ltd. Method for avoiding interference in a digital communication system
US7693488B2 (en) * 2004-09-30 2010-04-06 Vtech Telecommunications Limited System and method for asymmetric enhanced mode operation in a digital communication system
DE102012206272A1 (en) * 2012-04-17 2013-10-17 Beckhoff Automation Gmbh Fieldbus communication

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4174466A (en) * 1976-09-01 1979-11-13 Telefonaktiebolaget L M Ericsson Multi-party telephone system allowing speech connection between extensions as between extensions and an outer line
EP0120718A1 (en) * 1983-03-30 1984-10-03 Nec Corporation Multi-channel access (MCA) radio telephone system
US4731812A (en) * 1985-05-09 1988-03-15 Telefonaktiebolaget Lm Ericsson Installation with portable, wireless telephone sets

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4555805A (en) * 1980-03-14 1985-11-26 Harris Corporation Secure mobile telephone system
US4532635A (en) * 1983-08-19 1985-07-30 Rca Corporation System and method employing two hop spread spectrum signal transmissions between small earth stations via a satellite and a large earth station and structure and method for synchronizing such transmissions
JPS62195A (en) * 1985-06-04 1987-01-06 Nec Corp Mobile communication system
GB2229064B (en) * 1987-06-11 1990-12-12 Software Sciences Limited An area communications system
JPS6424648A (en) * 1987-07-21 1989-01-26 Fujitsu Ltd Privacy call equipment
US4841527A (en) * 1987-11-16 1989-06-20 General Electric Company Stabilization of random access packet CDMA networks

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4174466A (en) * 1976-09-01 1979-11-13 Telefonaktiebolaget L M Ericsson Multi-party telephone system allowing speech connection between extensions as between extensions and an outer line
EP0120718A1 (en) * 1983-03-30 1984-10-03 Nec Corporation Multi-channel access (MCA) radio telephone system
US4731812A (en) * 1985-05-09 1988-03-15 Telefonaktiebolaget Lm Ericsson Installation with portable, wireless telephone sets

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1100212A1 (en) * 1999-11-09 2001-05-16 Lucent Technologies Inc. Transmitting/receiving apparatus for electromagnetic signals
GB2404527A (en) * 2003-07-26 2005-02-02 Motorola Inc Baseband processing of control signals in a multi sector base station
GB2404527B (en) * 2003-07-26 2005-10-12 Motorola Inc A multi sector base station and method of operation therefor

Also Published As

Publication number Publication date
NO300569B1 (en) 1997-06-16
NO922786D0 (en) 1992-07-14
FI86123B (en) 1992-03-31
EP0511338A1 (en) 1992-11-04
FI905666A0 (en) 1990-11-15
FI86123C (en) 1992-07-10
FI905666A (en) 1992-03-31
DE69108897T2 (en) 1995-08-17
AU640542B2 (en) 1993-08-26
DE69108897D1 (en) 1995-05-18
AU8847691A (en) 1992-06-11
NO922786L (en) 1992-09-14
ATE121244T1 (en) 1995-04-15
EP0511338B1 (en) 1995-04-12
US5307371A (en) 1994-04-26

Similar Documents

Publication Publication Date Title
AU646113B2 (en) A radio transceiver system
US5329548A (en) Base station for a frequency hopping TDMA radio communication system
CN1104117C (en) Base station transceiver for FH/CDMA system
US6385190B1 (en) Mobile communications system which uses TDMA for speech data and OFDM for control/extended data
US6788729B1 (en) Frequency hopping method and base station
AU640542B2 (en) A radio transceiver system
WO1984000455A1 (en) Equipment for wireless telephone transmission
AU707804B2 (en) Point-multipoint radio transmission system
EP0715786B1 (en) Base station equipment using diversity reception
JP2003332940A (en) Mobile communication device
JPH08274679A (en) Portable telephone equipment
JPH06169272A (en) Diversity signal transmission system
JPH04332284A (en) Radio video signal communication equipment
WO1999027655A2 (en) Method for connection establishment, and transceiver
JPH0226132A (en) Mobile radio communication equipment
JPH104378A (en) Satellite communication system
JP2000224085A (en) Digital radio equipment
JPH04216218A (en) Communication system

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU GB NO US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1991919112

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1991919112

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1991919112

Country of ref document: EP