Recherche Images Maps Play YouTube Actualités Gmail Drive Plus »
Connexion
Les utilisateurs de lecteurs d'écran peuvent cliquer sur ce lien pour activer le mode d'accessibilité. Celui-ci propose les mêmes fonctionnalités principales, mais il est optimisé pour votre lecteur d'écran.

Brevets

  1. Recherche avancée dans les brevets
Numéro de publicationUS2410350 A
Type de publicationOctroi
Date de publication29 oct. 1946
Date de dépôt6 févr. 1943
Date de priorité6 févr. 1943
Numéro de publicationUS 2410350 A, US 2410350A, US-A-2410350, US2410350 A, US2410350A
InventeursEmile Labin, Grieg Donald D
Cessionnaire d'origineStandard Telephones Cables Ltd
Exporter la citationBiBTeX, EndNote, RefMan
Liens externes: USPTO, Cession USPTO, Espacenet
Method and means for communication
US 2410350 A
Résumé  disponible en
Images(3)
Previous page
Next page
Revendications  disponible en
Description  (Le texte OCR peut contenir des erreurs.)

:29, 1 94s. MAM E TAL. mam

METHOD AND MEANS OF COMMUNICATION Filed Feb. '6, 1945' 3 Sheet-$heet 1 v EM HQ} pomp a 52/56 19%. E. LABIN ETAL 2,410,35

METHOD AND MEANS OF COMMUNICATION Filed Feb. 6, 1945 I SSheets-Sheet 5 INVENTORS EMILE LflB/N DO/VHLD D. GR/EG Patented Oct. 29, 1946 METHOD AND MEANS OF COMIVIUNICATION Emile Labin, New York, and Donald D. Grieg,

Forest Hills, N. Y., assignors to Federal Telephone and Radio Corporation, Newark, N. .L, a

corporation of Delaware Application February 6, 1943, Serial No. 474,960

9 Claims.

This invention relates to improvements in methods and means of communication, and more particularly to arrangement for improving the selection and preventing interference between modulated pulse carriers having a pulsing frequency difference between them.

In the case of so-called multiplex communication systems, attempts have been made, for example, to use a single channel for transmitting intelligence from several sources by separate intelligence-modulated pulse trains which have a very slight frequency difference between them. Also, it may be desirable, at times, to transmit intelligence by means of pulsed high frequency carriers which differ from one another in pulsing rate by a slight amount. It is now possible, in either of these cases, to substantially eliminate the undesired signal per se but interference still results from the overlapping of certain pulses or high frequency carriers, causing sets of peaks. While these peaks themselves, which occur at more or less regular intervals, could be eliminated by suitable filters, a large amount of interference will still exist due to the signal modulation producing complex beats.

The primary object of the present invention is to provide a method and means applicable in the above-mentioned cases for eliminating the interference caused by such complex beats and thus permitting the selection of a clear desired signal.

Another object of the present invention is directed to the provision of a system for the transmission of intelligence by means of which a plurality of signals may be transmitted over a single channel which may be either wire or wireless, and to a receiver or a plurality of receivers each of which may pick out a desired signal with a minimum of interference.

The principles of the present invention are also applicable to arrangements for receiving signals through jamming or similar interference with a minimum loss and a maximum clarity.

Other objects and advantages of the present invention will appear from the following description of a specific embodiment and modifications thereof, in the accompanying drawings in which:

Fig. 1 is a block circuit diagram illustrating a preferred system according to the present in vention;

Fig. 2 is a series of curves illustrating the operation of the system illustrated in Fig. 1;

Fig. 3 is a second series of curves illustrating the adaptation of the system of Fig. 1 to another type of intelligence transmission.

As shown in Fig. 1, there may be provided a plurality of signal sources of which two, In and i2 are illustrated. In accordance with the first form of the invention, the signal sources may consist of separate sub-carriers in the form of trains of modulated pulses, the frequency of one train differing slightly from the frequency of the other train. This frequency difference may be cycles or less, or up to 1,000 cycles where, for example, the frequency of each pulse train is in the neighborhood of 12,000 cycles. The two (or more) pulse trains may be transmitted over a common channel It which may either be wired, or may, for example, be a common carrier wave. The receiver or receivers of which two, I6 and I0 are illustrated are connected or tuned to this common channel It so that they will receive both sets of pulses. In Fig. 2 (I) we have indicated a series of pulses a which may be derived from source A and at (II) a series of pulses 7) derived from source B. At the receiver I5, for example, these two trains of pulses of different frequency will produce a pulse signal somewhat as indicated in Fig. 2 (III). It will be noted that due to the slight frequency diiference, at certain intervals some of the pulses will overlap, producing peaks which, generally speaking, will be the sum of the individual overlapped pulses. At other points the two sets of pulses will be either adjacent. one another or more or less spaced apart. In accordance with the present invention, these incoming pulses are first impressed upon a first mixer l8 which is controlled by a blocker 20 whose wave may have somewhat the shape indicated in Fig. 2

(IV) so as to prevent the passing through of all pulses except those corresponding to the frequency of the pulse train from source A, allowance being made, of course, for pulse displacements or other changes due to modulating signals. When this blocking device 20 is applied to the mixer Hi, the resulting output in line 22 will be somewhat as indicated in Fig. 2 (V). It will be seen that all individual undesired pulses such as the pulses b have been eliminated but this does not eliminate the peaks or partial peaks caused by overlapping of the pulses b with the pulses it. Since these periods of overlapping will occur at predetermined intervals in accordance with the frequency difference between pulse trains, it would be possible to eliminate the peaks by suitable filters. However, in addition to the peaks themselves, the overlap between the two sets of pulses causes complex beats due to the modulation of the individual pulses, and these beats cause undesirable interference in the received intelligence. Accordingly, by the present invention, the output from lead 22 of the receiver is directed to a second blocking device 24 which may consist of a clipper 28 which takes off the top portions of the peaks reversing them by means of a shaper 30 and then applies them in a second mixer 26 to entirely eliminate those portions of the a pulses which are overlapped. The result of this operation is indicated in Fig. 2 (VI), wherein it can be noted that the first of the series of pulses illustrated, has now been entirely omitted, while the second pulse has been out in half by the elimination of its overlapping pulse. The remaining a pulses are not afiected. The fact that one of the retained pulses is smaller than the other pulses is of little consequence. It will produce no interference: if the-pulses are differentiated and the intelligence is controlled by the leadin edge of the retained pulses. In

Fig. 1, we have shown the output lead 30 from the second mixer 26, applied to a differentiating circuit 32, the output 34 from which. will have a wave shape of differentiated pulses a as indicated in Fig. 2 (VII).

The absence of a desired pulse indicated by the blank in the first line of Fig. 2 (VII) may produce a. low audible beat in the finally received signal. This can readily be eliminated by passing the received signals through a low-frequency rejection filter. In Fig. l, we have illustrated a demodulator 36 connected to the output lead 34. The output from this demodulator being fed through the rejection filter 38. The signal output from the filter 38 will, therefore, be substantially free of any interference caused by the simultaneous reception of a plurality of pulse trains.

The other receivers such as [6' will be similar to the receiver l6, although they may be synchronized in time, for example, to the signals from source B. In such a case the blocker 20 would act upon the first mixer 18' to eliminate all but the b pulses. The second block 24, the second mixer 26, the difierentiating circuit 32', the demodulator 36' and the low-pas filter 38 acting aspreviously described in connection with the receiver [6. c

It is to be understood that while we have illustrated two sources of signals and two receivers, the invention is applicable to arrangements including any number of signal sources in connection with one or more receivers. It will also be clear that provision may be made at each receiver for varying the first blocking device (20) to permit controllably picking out of the desired signal from any other undesired signals.

The principles of the present invention are also applicable to prevent interference between a desired high frequency carrier and an undesired high frequency carrier having the same high frequency carrier frequency but differing in pulsing rate or sub-carrier frequency. This second application is graphically illustrated in Fig. 3 in which line (VIII), shows for example, the upper half of a desired pulsed carrier wave a: while line (IX) similarly shows an undesired pulsed carrier 3 At certain intervals the two sub-carriers will progressivelyinterfere as indicated in line (X). If the receiver is periodically unblocked to eliminate all but the desired subcarrier 1:, the result will be as is shown in lines been distorted by interference and, in an actual case, there will be series of such distorted subcarriers as illustrated in the first three examples, in line (XII). For the purpose of eliminating all such distorted sub-carriers in this case, the second blocker will be initiated by a clipper, as before, but the blocking pulse will have a time lag which covers all of the distorted sub-carriers. This may be accomplished, as will be clear to those skilled in this art, by means of a suitable multivibrator circuit producing a blocking pulse as shown in line (IHII), The resultant signal will then be represented as in line QGIV) by pulsed sub-carriers a: between which, at certain intervals, a larger void will exist. However, this periodic absence of signal causes less interference than is caused by mere elimination of the undesired sub-carrier and the low frequency beat note which may result from the periodic absence of signal can be eliminated by passing the signals through a suitable low-pass rejection filter.

While the methods and means of the present invention are particularly applicable to systems of multiplex communication, it will also be seen that they provide an arrangement for eliminating interference due to jamming, if the jamming signal is not exactly synchronized with the intelligence to be received. Thus, returning to Fig. 1, if the source B were a modulated jammin pulse rather than a second signal source, the adverse effects of such jamming pulse will be substantially eliminated in the same manner as described in eliminating the undesired signal.

Throughout the present description and claims, the'term sub-carrier has been used in a broad sense to mean any periodic wave or pulse which is modulated by the signals to be transmitted. For example, where a pulse is itself modulated in accordance with intelligence, the pulse forms the sub-carrier, in other cases the sub-carrier may he a high frequency wave which is pulsemodulated in accordance with signals to be transmitted. I In contrast, in the former case a second common radio frequency carrier or channel may be used -to carry the modulated pulses, but this is not the interfering "sub-carrier to which reference is made, as this carrier merely acts as the common channel.

While we have described certain features of the present invention which are deemed essential to a complete understanding thereof, and while we have illustrated and described the invention in connection with certain specific embodiments, it is to be understood that the description is made only by way of example and not as a limitation on the scope of our invention as set forth in the objects and the accompanying claims.

We claim: a

l. The method of selecting a desired modulated pulse train from among a plurality of modulated pulse trains having a slight frequency difference relatively to the desired pulse train, which includes the steps of blocking out the undesired pulses whenever they do not overlap the desired pulses, and blocking out at least the pulse portions of those desired pulses which are overlapped by the undesired pulses.

2. The method according to claim 1, which includes the further step of eliminating the beat note caused by the absence of desired pulses.

3. The method for the transmission and reception of intelligence which includes the steps of simultaneously transmitting a plurality of intelligence modulated pulse sub-carriers having slightly different pulse repetition rates substantially simultaneously receiving these sub-carriers at a plurality of receiving stations, and at each receiving station selecting the desired intelligence by blocking out the undesired sub-carriers and blocking out those portions of the desired subcarrier which have been distorted by interference with the undesired sub-carriers.

4. In a selecting system for receivers adapted to receive a plurality of pulse sub-carriers havstage for periods corresponding to the frequency of the desired pulse train, means for clipping the pulses of the desired train which have been peaked by overlapping with undesired pulse trains, and further blocking means controlled by the corresponding peaks for blocking out at least the pulse portions of those desired pulses which were overlapped by the undesired pulses.

6. The combination according to claim 5, in combination with pulse difierentiating means 6 producing a signal in accordance with at least one of the edges of the desired pulses.

7. The combination according to claim 5, in combination with pulse difierentiating means producing a signal in accordance with at least one of the edges of the desired pulses, and a rejection filter for eliminating the beat note resulting from the periodic absence of signal of the desired pulse train caused by the last-mentioned blocking means.

8. A system of communication including in combination a plurality of transmitters, each transmitting intelligence over pulse sub-carriers difierentiating only in slightly different pulse rates, means providing a common transmitting channel for simultaneous transmission of the pulse sub-carriers of said transmitters, and one or more normally blocked receivers coupled to said common channel means, each receiver including unblocking means permitting reception of a desired sub-carrier, and blocking means for blocking out at least those portions of the desired sub-carriers distorted by the undesired subcarriers.

9. The combination according to claim 5, in combination with a rejection filter for eliminating the beat note resulting from the periodic absence of signal of the desired pulse train caused by the said last means.

EMILE LABIN. DONALD D. GRIEG.

Référencé par
Brevet citant Date de dépôt Date de publication Déposant Titre
US2523703 *25 juin 194626 sept. 1950Research CorpSystem for transmitting signal modulated pulses
US2579071 *16 juil. 194718 déc. 1951Rca CorpTime division multiplex system
US2580421 *9 nov. 19451 janv. 1952Radio Patents CorpCross-talk compensation in pulse multiplex system
US2597038 *9 nov. 194820 mai 1952Int Standard Electric CorpTwo-way electric pulse communication system
US2654885 *19 déc. 19496 oct. 1953Padevco IncMultiplex frequency modulation communication system
US2672526 *19 mars 195116 mars 1954Int Standard Electric CorpPulse electrical telecommunication system
US2681384 *1 oct. 195115 juin 1954Radio Patents CompanyCross-talk control in pulse multiplex transmission systems
US2719188 *5 mai 195027 sept. 1955Bell Telephone Labor IncNon-synchronous time division multiplex telephone transmission
US6049706 *21 oct. 199811 avr. 2000Parkervision, Inc.Integrated frequency translation and selectivity
US6061551 *21 oct. 19989 mai 2000Parkervision, Inc.Method and system for down-converting electromagnetic signals
US6061555 *21 oct. 19989 mai 2000Parkervision, Inc.Method and system for ensuring reception of a communications signal
US6091940 *21 oct. 199818 juil. 2000Parkervision, Inc.Method and system for frequency up-conversion
US626651818 août 199924 juil. 2001Parkervision, Inc.Method and system for down-converting electromagnetic signals by sampling and integrating over apertures
US635373523 août 19995 mars 2002Parkervision, Inc.MDG method for output signal generation
US63703713 mars 19999 avr. 2002Parkervision, Inc.Applications of universal frequency translation
US642153418 août 199916 juil. 2002Parkervision, Inc.Integrated frequency translation and selectivity
US654272216 avr. 19991 avr. 2003Parkervision, Inc.Method and system for frequency up-conversion with variety of transmitter configurations
US656030116 avr. 19996 mai 2003Parkervision, Inc.Integrated frequency translation and selectivity with a variety of filter embodiments
US658090216 avr. 199917 juin 2003Parkervision, Inc.Frequency translation using optimized switch structures
US664725018 août 199911 nov. 2003Parkervision, Inc.Method and system for ensuring reception of a communications signal
US668749316 avr. 19993 févr. 2004Parkervision, Inc.Method and circuit for down-converting a signal using a complementary FET structure for improved dynamic range
US669412810 mai 200017 févr. 2004Parkervision, Inc.Frequency synthesizer using universal frequency translation technology
US67045493 janv. 20009 mars 2004Parkvision, Inc.Multi-mode, multi-band communication system
US67045583 janv. 20009 mars 2004Parkervision, Inc.Image-reject down-converter and embodiments thereof, such as the family radio service
US67983515 avr. 200028 sept. 2004Parkervision, Inc.Automated meter reader applications of universal frequency translation
US681348520 avr. 20012 nov. 2004Parkervision, Inc.Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US683665030 déc. 200228 déc. 2004Parkervision, Inc.Methods and systems for down-converting electromagnetic signals, and applications thereof
US687383610 mai 200029 mars 2005Parkervision, Inc.Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US687981714 mars 200012 avr. 2005Parkervision, Inc.DC offset, re-radiation, and I/Q solutions using universal frequency translation technology
US696373412 déc. 20028 nov. 2005Parkervision, Inc.Differential frequency down-conversion using techniques of universal frequency translation technology
US69758488 nov. 200213 déc. 2005Parkervision, Inc.Method and apparatus for DC offset removal in a radio frequency communication channel
US70068053 janv. 200028 févr. 2006Parker Vision, Inc.Aliasing communication system with multi-mode and multi-band functionality and embodiments thereof, such as the family radio service
US701028616 mai 20017 mars 2006Parkervision, Inc.Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US701055913 nov. 20017 mars 2006Parkervision, Inc.Method and apparatus for a parallel correlator and applications thereof
US70166634 mars 200221 mars 2006Parkervision, Inc.Applications of universal frequency translation
US702778610 mai 200011 avr. 2006Parkervision, Inc.Carrier and clock recovery using universal frequency translation
US703937213 avr. 20002 mai 2006Parkervision, Inc.Method and system for frequency up-conversion with modulation embodiments
US705050818 juil. 200223 mai 2006Parkervision, Inc.Method and system for frequency up-conversion with a variety of transmitter configurations
US70542964 août 200030 mai 2006Parkervision, Inc.Wireless local area network (WLAN) technology and applications including techniques of universal frequency translation
US70723904 août 20004 juil. 2006Parkervision, Inc.Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US70724277 nov. 20024 juil. 2006Parkervision, Inc.Method and apparatus for reducing DC offsets in a communication system
US70760117 févr. 200311 juil. 2006Parkervision, Inc.Integrated frequency translation and selectivity
US70821719 juin 200025 juil. 2006Parkervision, Inc.Phase shifting applications of universal frequency translation
US70853359 nov. 20011 août 2006Parkervision, Inc.Method and apparatus for reducing DC offsets in a communication system
US710702812 oct. 200412 sept. 2006Parkervision, Inc.Apparatus, system, and method for up converting electromagnetic signals
US711043514 mars 200019 sept. 2006Parkervision, Inc.Spread spectrum applications of universal frequency translation
US71104444 août 200019 sept. 2006Parkervision, Inc.Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US719094112 déc. 200213 mars 2007Parkervision, Inc.Method and apparatus for reducing DC offsets in communication systems using universal frequency translation technology
US719424627 déc. 200420 mars 2007Parkervision, Inc.Methods and systems for down-converting a signal using a complementary transistor structure
US721889912 oct. 200415 mai 2007Parkervision, Inc.Apparatus, system, and method for up-converting electromagnetic signals
US72189075 juil. 200515 mai 2007Parkervision, Inc.Method and circuit for down-converting a signal
US722474913 déc. 200229 mai 2007Parkervision, Inc.Method and apparatus for reducing re-radiation using techniques of universal frequency translation technology
US723396918 avr. 200519 juin 2007Parkervision, Inc.Method and apparatus for a parallel correlator and applications thereof
US72367544 mars 200226 juin 2007Parkervision, Inc.Method and system for frequency up-conversion
US72458863 févr. 200517 juil. 2007Parkervision, Inc.Method and system for frequency up-conversion with modulation embodiments
US727216410 déc. 200218 sept. 2007Parkervision, Inc.Reducing DC offsets using spectral spreading
US729283529 janv. 20016 nov. 2007Parkervision, Inc.Wireless and wired cable modem applications of universal frequency translation technology
US72958265 mai 200013 nov. 2007Parkervision, Inc.Integrated frequency translation and selectivity with gain control functionality, and applications thereof
US730824210 août 200411 déc. 2007Parkervision, Inc.Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same
US73216404 juin 200322 janv. 2008Parkervision, Inc.Active polyphase inverter filter for quadrature signal generation
US732173510 mai 200022 janv. 2008Parkervision, Inc.Optical down-converter using universal frequency translation technology
US737641016 févr. 200620 mai 2008Parkervision, Inc.Methods and systems for down-converting a signal using a complementary transistor structure
US73795152 mars 200127 mai 2008Parkervision, Inc.Phased array antenna applications of universal frequency translation
US737988318 juil. 200227 mai 2008Parkervision, Inc.Networking methods and systems
US738629225 oct. 200410 juin 2008Parkervision, Inc.Apparatus, system, and method for down-converting and up-converting electromagnetic signals
US738910024 mars 200317 juin 2008Parkervision, Inc.Method and circuit for down-converting a signal
US743391018 avr. 20057 oct. 2008Parkervision, Inc.Method and apparatus for the parallel correlator and applications thereof
US745445324 nov. 200318 nov. 2008Parkervision, Inc.Methods, systems, and computer program products for parallel correlation and applications thereof
US746058418 juil. 20022 déc. 2008Parkervision, Inc.Networking methods and systems
US748368627 oct. 200427 janv. 2009Parkervision, Inc.Universal platform module and methods and apparatuses relating thereto enabled by universal frequency translation technology
US749634225 oct. 200424 févr. 2009Parkervision, Inc.Down-converting electromagnetic signals, including controlled discharge of capacitors
US751589614 avr. 20007 avr. 2009Parkervision, Inc.Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US752952218 oct. 20065 mai 2009Parkervision, Inc.Apparatus and method for communicating an input signal in polar representation
US753947417 févr. 200526 mai 2009Parkervision, Inc.DC offset, re-radiation, and I/Q solutions using universal frequency translation technology
US754609622 mai 20079 juin 2009Parkervision, Inc.Frequency up-conversion using a harmonic generation and extraction module
US755450815 janv. 200830 juin 2009Parker Vision, Inc.Phased array antenna applications on universal frequency translation
US759942117 avr. 20066 oct. 2009Parkervision, Inc.Spread spectrum applications of universal frequency translation
US762037816 juil. 200717 nov. 2009Parkervision, Inc.Method and system for frequency up-conversion with modulation embodiments
US765314525 janv. 200526 janv. 2010Parkervision, Inc.Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations
US765315817 févr. 200626 janv. 2010Parkervision, Inc.Gain control in a communication channel
US769323022 févr. 20066 avr. 2010Parkervision, Inc.Apparatus and method of differential IQ frequency up-conversion
US76935022 mai 20086 avr. 2010Parkervision, Inc.Method and system for down-converting an electromagnetic signal, transforms for same, and aperture relationships
US769791621 sept. 200513 avr. 2010Parkervision, Inc.Applications of universal frequency translation
US772484528 mars 200625 mai 2010Parkervision, Inc.Method and system for down-converting and electromagnetic signal, and transforms for same
US777368820 déc. 200410 août 2010Parkervision, Inc.Method, system, and apparatus for balanced frequency up-conversion, including circuitry to directly couple the outputs of multiple transistors
US782240112 oct. 200426 oct. 2010Parkervision, Inc.Apparatus and method for down-converting electromagnetic signals by controlled charging and discharging of a capacitor
US782681720 mars 20092 nov. 2010Parker Vision, Inc.Applications of universal frequency translation
US78651777 janv. 20094 janv. 2011Parkervision, Inc.Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US78947897 avr. 200922 févr. 2011Parkervision, Inc.Down-conversion of an electromagnetic signal with feedback control
US792963814 janv. 201019 avr. 2011Parkervision, Inc.Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US79360229 janv. 20083 mai 2011Parkervision, Inc.Method and circuit for down-converting a signal
US793705931 mars 20083 mai 2011Parkervision, Inc.Converting an electromagnetic signal via sub-sampling
US799181524 janv. 20082 août 2011Parkervision, Inc.Methods, systems, and computer program products for parallel correlation and applications thereof
US80192915 mai 200913 sept. 2011Parkervision, Inc.Method and system for frequency down-conversion and frequency up-conversion
US80363045 avr. 201011 oct. 2011Parkervision, Inc.Apparatus and method of differential IQ frequency up-conversion
US807779724 juin 201013 déc. 2011Parkervision, Inc.Method, system, and apparatus for balanced frequency up-conversion of a baseband signal
US816019631 oct. 200617 avr. 2012Parkervision, Inc.Networking methods and systems
US816053414 sept. 201017 avr. 2012Parkervision, Inc.Applications of universal frequency translation
US819010826 avr. 201129 mai 2012Parkervision, Inc.Method and system for frequency up-conversion
US81901164 mars 201129 mai 2012Parker Vision, Inc.Methods and systems for down-converting a signal using a complementary transistor structure
US82238987 mai 201017 juil. 2012Parkervision, Inc.Method and system for down-converting an electromagnetic signal, and transforms for same
US822428122 déc. 201017 juil. 2012Parkervision, Inc.Down-conversion of an electromagnetic signal with feedback control
US822902319 avr. 201124 juil. 2012Parkervision, Inc.Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
US823385510 nov. 200931 juil. 2012Parkervision, Inc.Up-conversion based on gated information signal
US829540610 mai 200023 oct. 2012Parkervision, Inc.Universal platform module for a plurality of communication protocols
US82958007 sept. 201023 oct. 2012Parkervision, Inc.Apparatus and method for down-converting electromagnetic signals by controlled charging and discharging of a capacitor
US834061822 déc. 201025 déc. 2012Parkervision, Inc.Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships
US84070619 mai 200826 mars 2013Parkervision, Inc.Networking methods and systems
US84469949 déc. 200921 mai 2013Parkervision, Inc.Gain control in a communication channel
US859422813 sept. 201126 nov. 2013Parkervision, Inc.Apparatus and method of differential IQ frequency up-conversion
Classifications
Classification aux États-Unis370/201, 370/497
Classification internationaleH04L5/02, H04L5/04
Classification coopérativeH04L5/04
Classification européenneH04L5/04