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51. 发明专利

TR200002016T2 未知
公开(公告)号：TR200002016T2
公开(公告)日：2001-01-22
申请号：TR200002016
申请日：1999-01-12
申请人： ERICSSON INC
发明人： SOUROUR ESSAM , BOTTOMLEY GREG , RAMESH RAJAARAM , CHENNAKESHU SANDEEP
IPC分类号： H04B1/711 , H04B1/709 , H04B1/7113 , H04B7/26 , H04B1/707
摘要： Multipath delay estimation of a direct sequence spread spectrum (DS-SS) signal transmitted in a multipath fading channel is accomplished by measuring the envelope of the signal to determine a new delay estimate. Delay estimates are also obtained in ray strength order, by subtracting out the influence of the stronger rays on the weaker ones. This subtraction approach can be performed iteratively, allowing further refinement of the delay estimates. Delay estimates can also be determined by minimizing the mean square error (MSE) between a measured correlation function and a modeled correlation function. The minimum mean square error (MMSE) approach can performed iteratively, to further refine the delay estimates. Maximum likelihood (ML) delay estimates can also be obtained by exploiting side information regarding the transmit and receive pulse shapes.

52. 发明专利

AU5021500A Multiple mode radiotelephones including glue circuits and related methods and circuits 未知
公开(公告)号：AU5021500A
公开(公告)日：2001-01-02
申请号：AU5021500
申请日：2000-05-16
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , RYDBECK NILS
IPC分类号： H04B1/40 , H04B7/26 , H04M1/00 , H04M1/253 , H04Q7/38

53. 发明专利

BR9906840A 未知
公开(公告)号：BR9906840A
公开(公告)日：2000-10-17
申请号：BR9906840
申请日：1999-01-12
申请人： ERICSSON INC
发明人： SOUROUR ESSAN , BOTTOMLEY GREG , RAMESH RAJARAM , CHENNAKESHU SANDEEP
IPC分类号： H04B1/711 , H04B1/709 , H04B1/7113 , H04B7/26 , H04B1/707
摘要： Multipath delay estimation of a direct sequence spread spectrum (DS-SS) signal transmitted in a multipath fading channel is accomplished by measuring the envelope of the signal to determine a new delay estimate. Delay estimates are also obtained in ray strength order, by subtracting out the influence of the stronger rays on the weaker ones. This subtraction approach can be performed iteratively, allowing further refinement of the delay estimates. Delay estimates can also be determined by minimizing the mean square error (MSE) between a measured correlation function and a modeled correlation function. The minimum mean square error (MMSE) approach can performed iteratively, to further refine the delay estimates. Maximum likelihood (ML) delay estimates can also be obtained by exploiting side information regarding the transmit and receive pulse shapes.

54. 发明专利

AU724590B2 Error correction with two block codes 未知
公开(公告)号：AU724590B2
公开(公告)日：2000-09-28
申请号：AU4655997
申请日：1997-09-29
申请人： ERICSSON INC
发明人： WANG YI-PIN E , CHENNAKESHU SANDEEP , DENT PAUL , BALACHANDRAN KUMAR
IPC分类号： H03M13/37 , G06F11/10 , H03M13/00 , H03M13/29 , H04L1/00 , H04L1/06 , H04L1/18
摘要： The invention relates to a method for decoding a received codeword repeated at a receiver station through diversity means, wherein each repetition of the received codeword includes an information vector and redundancy vector. The method comprises inputting one or more of said information vectors (Î) in said received codewords to a series of parallel decoders (106), inputting one or more of said redundancy vectors (P1, ..., PL) in said received codewords to said parallel decoders (106), decoding the information vectors separately in said parallel decoders (106) to generate a plurality of estimates ( @ ) of the information sequence, and combining (108) at least two estimates of the information sequence to generate a composite estimate.

55. 发明专利

NO20002280A 未知
公开(公告)号：NO20002280A
公开(公告)日：2000-06-13
申请号：NO20002280
申请日：2000-04-28
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , IRVIN DAVID R , TOWNSEND DAVID P , BRIGHT RANDY
IPC分类号： B60R11/02 , H04B1/38 , H04B1/40 , H04B7/26 , H04M1/00 , H04M1/60 , H04M1/72
CPC分类号： H04B1/3822 , B60R11/0241 , H04M1/6091 , H04M2250/02

56. 发明专利

BR9807250A 未知
公开(公告)号：BR9807250A
公开(公告)日：2000-05-02
申请号：BR9807250
申请日：1998-02-17
申请人： ERICSSON INC
发明人： RAMESH RAJARAM , CHENNAKESHU SANDEEP
IPC分类号： H04L9/30 , H04B7/005 , H04L9/36
摘要： A fading compensation apparatus and method are provided in which blocks of the analog AM signal (e.g., voice) are time-compressed at a transmitter. Gaps in the time-compressed signal are filled with pilot symbols (or similar complex waveforms) having known characteristics, such as predetermined amplitudes. The time-compressed analog AM signal (e.g., SSB or VSB) is transmitted over the fading channel. At an analog AM receiver, an estimate of the fading that occurred in the transmission channel is made by observing the amplitude of the received pilot symbols at discrete points in time, and interpolating to determine the amount of fading that occurred across the total transmitted signal. A fading compensator compares the received faded time-compressed signal with the interpolation results, and adjusts the amplitude and phase of the received signal accordingly to compensate for the fading that occurred in the transmission channel. The compensated analog AM signal is time expanded and output to a user.

57. 发明专利

NO20002280D0 未知
公开(公告)号：NO20002280D0
公开(公告)日：2000-04-28
申请号：NO20002280
申请日：2000-04-28
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , IRVIN DAVID R , TOWNSEND DAVID P , BRIGHT RANDY
IPC分类号： B60R11/02 , H04B1/38 , H04B1/40 , H04B7/26 , H04M1/00 , H04M1/60 , H04M1/72 , H04B
摘要： A radiotelephone includes a base unit mounted within the vehicle having a wide area transceiver for communicating with a station outside the vehicle, a control unit disposed in the vehicle remotely from the base unit, and a local area network for establishing a communication link between the base unit and the control unit. The local area network is adapted to transmit control and data signals between the base unit and the control unit. The control unit includes a keypad for entering commands and data that are transmitted to the base unit via the local area network, and a display for displaying information to the user. The control unit may also include a speaker and microphone. Alternatively, the speaker and microphone may be contained in a remote audio unit that is linked to the base unit via the local area network. The control unit may, for example, be incorporated into the steering wheel of a vehicle while the base unit is concealed in the trunk or under the seat of the vehicle.

58. 发明专利

AU1443300A Method and apparatus to communicate auxiliary and location information between cellular telephone network and global positioning system 未知
公开(公告)号：AU1443300A
公开(公告)日：2000-04-26
申请号：AU1443300
申请日：1999-10-06
申请人： ERICSSON INC
发明人： WANG YI-PIN ERIC , CHENNAKESHU SANDEEP
IPC分类号： G01S1/00 , G01S5/00 , G01S19/25 , G01S19/37 , G01S19/44 , G01S19/46 , H04Q7/34 , H04Q7/36 , H04B7/26
摘要： A method and apparatus for communicating auxiliary information between a cellular telephone network and a GPS receiver positioned within a mobile station and identifying the location of the mobile station. A dedicated channel between the mobile station and the network is assigned by the network and uplink timing between the mobile station and the network is adjusted. The network requests auxiliary information and also requests the GPS receiver to perform a GPS code shift search at a common reference time. Upon receiving the auxiliary information, the network transmits the auxiliary information to the GPS receiver which then performs the GPS code shift search. The GPS receiver incorporates a bank of correlators and accumulators to perform multiple parallel searches for various Doppler frequency shifts resulting from a moving GPS receiver. The mobile station subsequently transmits the location information to the cellular telephone network.

59. 发明专利

AU716138B2 Method and apparatus for symbol decoding using a variable number of survivor paths 未知
公开(公告)号：AU716138B2
公开(公告)日：2000-02-17
申请号：AU1423897
申请日：1996-12-23
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , KOILPILLAI RAVINDER DAVID , ANDERSON JOHN B
IPC分类号： H03M13/23 , H03M13/41 , H04L1/00 , H04L25/03 , H03M13/00
摘要： A low complexity, high performance trellis decoder adapts the complexity of the trellis decoding process based on a current condition of the communications system. A trellis structure of nodes and branches is developed to decode the sequence of symbols received over a communications channel. Each set of nodes in the trellis represents the possible values of a received symbol at one time instant. Each branch defines a specific transition between nodes at different time instants, and each branch has an associated branch metric or weight. A linkage of branches between the nodes and the trellis defines a path through the trellis that represents one possible symbol sequence, and an accumulated metric/weight is generated for each possible path through the trellis. A variable number M survivor paths through the trellis is determined based on their accumulated path metric/weights. The value of the variable M depends on the current condition of the communications system. Once the value of M is adapted to the current condition, the sequence of received symbols is decoded using M survivor paths through the trellis.

60. 发明专利

DE69604303T2 未知
公开(公告)号：DE69604303T2
公开(公告)日：2000-01-13
申请号：DE69604303
申请日：1996-12-23
申请人： ERICSSON INC
发明人： CHENNAKESHU SANDEEP , RYDBECK NILS , HASSAN AMER , DENT PAUL
IPC分类号： H04B7/26 , H04B7/005 , H04B7/185 , H04W52/06 , H04W52/48
摘要： A method and system for transmitting short data messages in a control station-based TDMA radiocommunication system. According to exemplary embodiments, selected TDMA frames are assigned as message frames, and one or more data slots from each message frame are assigned to transmitter/receivers. Data messages can be encoded and transmitted multiple times, at an increased power level, from a control station to a transmitter/receiver over the appropriate data slots in each message frame. The selected TDMA frames are preferably slow associated control channel frames.

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