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101. 发明专利

AU1710499A Method and apparatus for frequency acquisition and tracking for ds-ss cdma receivers 未知
公开(公告)号：AU1710499A
公开(公告)日：1999-07-05
申请号：AU1710499
申请日：1998-12-08
申请人： ERICSSON INC
发明人： BOTTOMLEY GREGORY E , TOY RAYMOND L , CHENNAKESHU SANDEEP , MOLNAR KARL J
IPC分类号： H04B1/7075 , H04B1/7085 , H04B1/707
摘要： Systems and methods for frequency acquisition and channel tracking in a direct sequence code division multiple access system are described. Frequency estimates are prepared and refined, which estimates are also used in the channel tracking process.

102. 发明专利

CA2315157A1 METHOD AND APPARATUS FOR FREQUENCY ACQUISITION AND TRACKING FOR DS-SS CDMA RECEIVERS 未知
公开(公告)号：CA2315157A1
公开(公告)日：1999-06-24
申请号：CA2315157
申请日：1998-12-08
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , MOLNAR KARL J , BOTTOMLEY GREGORY E , TOY RAYMOND L
IPC分类号： H04B1/7075 , H04B1/7085 , H04B1/707
摘要： Systems and methods for frequency acquisition and channel tracking in a direct sequence code division multiple access system are described. Frequency estimates are prepared and refined, which estimates are also used in the channel tracking process.

103. 发明专利

CA2310084A1 METHOD AND APPARATUS FOR PERFORMING BEAM SEARCHING IN A RADIO COMMUNICATION SYSTEM 未知
公开(公告)号：CA2310084A1
公开(公告)日：1999-05-27
申请号：CA2310084
申请日：1998-10-22
申请人： ERICSSON INC
发明人： BOTTOMLEY GREGORY E , CHENNAKESHU SANDEEP , MOLNAR KARL J
IPC分类号： H04B7/185 , H04W16/28 , H04Q7/36
摘要： A radio communication system includes a base station having a directional antenna for generating a plurality of beams. A first set of the beams is used to receive signals which are decoded at the base station. A second set of the beams is used for interrogating a cell to identify beams which should be added to the first set of beams (for example, in response to mobile terminals entering the cell). In one embodiment, the second set of beams comprises a plurality of searcher beams produced by a fixed-beam phased array antenna. In a second embodiment, the second set of beams comprises a single searcher beam which is scanned through the cell by an adaptive phased array antenna. The radio communication system can be used to communicate with indoor mobile terminals through a plurality of radio heads, and also can be used to communicate with orbiting satellites.

104. 发明专利

AU7182298A Despreading of direct sequence spread spectrum communicationssignals 未知
公开(公告)号：AU7182298A
公开(公告)日：1998-06-03
申请号：AU7182298
申请日：1997-11-12
申请人： ERICSSON INC
发明人： BOTTOMLEY GREGORY E , RAMESH RAJARAM , DENT PAUL W , CHENNAKESHU SANDEEP
IPC分类号： H04B7/26 , H04B1/707 , H04B1/709 , H04B7/00
摘要： The disclosure presents a number of reduced complexity architectures for despreading direct sequence spread spectrum communications signals. In a first despreading architecture for a sequence removal unit, received chip-spaced complex samples are negated in accordance with the processed phase of a complex spreading sequence. Furthermore, the in-phase and quadrature phase sample values are switched for each other in accordance with the processed phase. In a second despreading architecture, in a sequence removal unit, received chip-spaced complex samples are processed in the logarithmic domain, with the phase of the complex spreading sequence added to the detected phase, and the resulting complex signal then converted back to Cartesian coordinates. In a third despreading architecture for a correlator, sequence removal and correlation are performed in the logarithmic domain with the amplitudes and phases for the resulting complex signal arithmetically averaged and then converted back to Cartesian coordinates. In a fourth despreading architecture also for a correlator, sequence removal and correlation are performed in the logarithmic domain using circular averaging. In a fifth despreading architecture also for a correlator, wherein multiple component sequences are combined together to form an overall sequence, and wherein one of the multiple component sequences is shared by all channels, a common sequence removal is provided for removal of the shared sequence from all channels. The resulting signals are then sent to a plurality of individual correlators for removal of channel specific sequences.

105. 发明专利

CA2271474A1 DESPREADING OF DIRECT SEQUENCE SPREAD SPECTRUM COMMUNICATIONS SIGNALS 未知
公开(公告)号：CA2271474A1
公开(公告)日：1998-05-22
申请号：CA2271474
申请日：1997-11-12
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , DENT PAUL W , RAMESH RAJARAM , BOTTOMLEY GREGORY E
IPC分类号： H04B7/26 , H04B1/707 , H04B1/709 , H04L27/34
摘要： The disclosure presents a number of reduced complexity architectures for despreading direct sequence spread spectrum communications signals. In a first despreading architecture for a sequence removal unit, received chip-spaced complex samples are negated in accordance with the processed phase of a complex spreading sequence. Furthermore, the in-phase and quadrature phase sample values are switched for each other in accordance with the processed phase. In a second despreading architecture, in a sequence removal unit, received chip-spaced complex samples are processed in the logarithmic domain, with the phase of the complex spreading sequence added to the detected phase, and the resulting complex signal then converted back to Cartesian coordinates. In a third despreading architecture for a correlator, sequence removal and correlation are performed in the logarithmic domain with the amplitudes and phases for the resulting complex signal arithmetically averaged and then converted back to Cartesian coordinates. In a fourth despreading architecture also for a correlator, sequence removal and correlation are performed in the logarithmic domain using circular averaging. In a fifth despreading architecture also for a correlator, wherein multiple component sequences are combined together to form an overall sequence, and wherein one of the multiple component sequences is shared by all channels, a common sequence removal is provided for removal of the shared sequence from all channels. The resulting signals are then sent to a plurality of individual correlators for removal of channel specific sequences.

106. 发明专利

CA2260911A1 METHOD AND APPARATUS FOR ENABLING MOBILE-TO-MOBILE CALLS IN A COMMUNICATION SYSTEM 未知
公开(公告)号：CA2260911A1
公开(公告)日：1998-02-05
申请号：CA2260911
申请日：1997-07-23
申请人： ERICSSON INC
发明人： RAMESH RAJARAM , CHENNAKESHU SANDEEP , DENT PAUL W , REINHOLD STANLEY L
IPC分类号： H04L9/08 , H04Q7/38 , H04B7/15 , H04B7/185 , H04B7/26 , H04L9/32 , H04Q7/22
摘要： A communication system is disclosed which reduces loop delay when a first wireless phone calls a second wireless phone wherein the first and second phones are served by the same relay station. The communication system includ es a relay station for communicating with the first and second wireless phones. A transponder located in the relay station relays signals received from one mobile station on a first frequency band to another mobile station on a seco nd frequency band. In addition, the transponder sends the received signals to a controller which controls the operation of the transponder using control information.

107. 发明专利

AU3151197A Apparatus and method for secure commmunication based on channel characteristics 未知
公开(公告)号：AU3151197A
公开(公告)日：1998-01-07
申请号：AU3151197
申请日：1997-06-06
申请人： ERICSSON INC
发明人： HASSAN AMER A , HERSHEY JOHN E , CHENNAKESHU SANDEEP
IPC分类号： G09C1/00 , H04L9/08
摘要： Characteristics of a communication channel are used to establish key sequences for use in encrypting communicated information. In one embodiment, these characteristics are the impedances of the channel viewed from one transceiver to the other and vice versa. The keys can be established with computations equivalent to a bounded distance decoding procedure, and the decoder used to establish a key may be used for processing the subsequent data transmission. Compared to classical and public-key cryptographic systems, an alternative mechanism for establishing and sharing key sequences that depends on a physical process is provided in which each party need not generate a pseudo-random quantity because the necessary randomness is provided by the properties of the communication channel itself. By using a channel decoder, the probability of two users establishing the same secret key is substantially unity, and the probability of an eavesdropper establishing the same key is substantially zero. Also, the number of possible keys is large enough that finding the correct one by exhaustive search is impractical.

108. 发明专利

AU2582697A Circuitry and method for initiating communication between communication stations of a radio communication system 未知
公开(公告)号：AU2582697A
公开(公告)日：1997-10-22
申请号：AU2582697
申请日：1997-03-28
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , WANG YI-PIN ERIC , BALACHANDRAN KUMAR
IPC分类号： H04B7/185 , H04W68/00 , H04W68/02 , H04W88/18 , H04Q7/38 , H04Q7/10 , H04Q7/12 , H04L1/08
摘要： A method and associated circuitry for initiating communication between a network station and a user terminal of a radiotelephonic communication system, such as a satellite-cellular communication system. When communication is to be initiated, a paging signal is transmitted by a network station to the user terminal. When the user terminal detects the paging signal, an acknowledgment signal is generated by the user terminal and encoded to increase the margin of the acknowledgment signal. An increased-margin acknowledgment signal acknowledging reception of the paging signal is transmitted to facilitate communication of the acknowledgment signal back to the network station.

109. 发明专利

AU1349797A High-penetration transmission method for a radiocommunication system 未知
公开(公告)号：AU1349797A
公开(公告)日：1997-07-28
申请号：AU1349797
申请日：1996-12-23
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , RYDBECK NILS , HASSAN AMER A , DENT PAUL W
IPC分类号： H04B7/15 , H04B7/185 , H04J3/00 , H04L1/08 , H04Q7/22 , H04B7/212
摘要： A method and system for increasing the signal margin of a radiocommunication link to provide a short message service which is reliable, even under non-ideal conditions. According to the method, short alphanumeric messages can be transmitted over the broadcast control channel of a digital radiocommunication link, or another communication channel consisting of one or more slots from successive frames in a TDMA communication link. An increase in transmission power is used in combination with repetition to increase effective signal margin without complications in the mobile unit design, significant delay, or co-channel interference. Where a more significant increase in signal margin is desired, when a longer message is required, or for voice messages, the message may be stored and the mobile unit alerted of the message.

110. 发明专利

AU4900596A Establishment of cryptographic keys in radio networks 未知
公开(公告)号：AU4900596A
公开(公告)日：1996-08-07
申请号：AU4900596
申请日：1996-01-19
申请人： ERICSSON INC
发明人： HASSAN AMER A , HERSHEY JOHN E , CHENNAKESHU SANDEEP
IPC分类号： H04L9/16 , H04B17/00 , H04K1/00 , H04L9/08 , H04Q7/38
摘要： Characteristics of the radio channel are used to establish key sequences for use in encrypting communicated information. These characteristics are the short-term reciprocity and rapid spatial decorrelation of phase of the radio channel. The keys can be established with computations equivalent to a bounded distance decoding procedure, and the decoder used to establish a key may be used for processing the subsequent data transmission. Compared to classical and public-key systems, an alternative mechanism for establishing and sharing key sequences that depends on a physical process is provided in which each party need not generate a pseudorandom quantity because the necessary randomness is provided by the temporal and spatial non-stationarity of the communication channel itself. By using a channel decoder, the probability of two users establishing the same secret key is substantially unity, and the probability of an eavesdropper establishing the same key is substantially zero. Also, the number of possible keys is large enough that finding the correct one by exhaustive search is impractical.

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