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公开(公告)号：JP2000244429A
公开(公告)日：2000-09-08
申请号：JP2000037109
申请日：2000-02-15
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LOU HUI-LING , SAYEED ZULFIQUAR , WEERACKODY VIJITHA
IPC: H04B7/185 , H04B7/216 , H04H20/57 , H04H40/90 , H04J11/00 , H04J13/00 , H04L1/00 , H04H1/00 , H04H1/04
Abstract: PROBLEM TO BE SOLVED: To eliminate the need of waiting time length corresponding to the comparatively long interleave length of a main program channel and to avoid large delay until the reproduction of a program by installing a tuning channel whose interleave length is set to be shorter than the main program channel. SOLUTION: A code division multiplex(CDM) satellite broadcasting system 100 has a first satellite 110 and a second satellite 120 operating at a broadcasting mode. The CDM satellite broadcasting system 100 has plural ground repeaters like a ground repeater 140 as an option. In the DM satellite broadcasting system 100, tuning channels reducing delay when a moving receiver 150 is tuned to a selected program channel at first are installed in accordance with respective program channels. In the tuning channels, interleaving length shorter than a corresponding main program channel is used in the case of an interleave processing.
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2.发明专利
公开(公告)号：JPH1022984A
公开(公告)日：1998-01-23
申请号：JP6562997
申请日：1997-03-19
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SAYEED ZULFIQUAR , WEERACKODY VIJITHA
Abstract: PROBLEM TO BE SOLVED: To provide an adaptive hybrid ARQ scheme by deciding a channel state based on the frequency of reception notice from a receiver. SOLUTION: A data source 11 supplies data to be transmitted to a frame assembly module 12 and a module transmits a receiver packet through an antenna 13 and receives reception notice data from the receiver through an antenna 14. When much NACK are returned from the receiver, strong FEC is used and the ARQ scheme is obtained. When an ACK signal is received, encoding is not used or weak FEC is used to obtain the AQR scheme.
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公开(公告)号：CA2317974C
公开(公告)日：2016-02-02
申请号：CA2317974
申请日：2000-09-08
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RIAZI HABIB , SAYEED ZULFIQUAR , ZHENG DUNMIN
Abstract: A terrestrial repeater is disclosed for use in a satellite transmission system that may also include a plurality of satellites. The terrestrial repeaters are implemented as OFDM transmitters to minimize the channel impairments caused by multi-path propagation. The OFDM terrestrial repeaters differentially encode the transmitted signal over frequency, as opposed to time, in order to avoid channel phase distortion. The OFDM receiver allocates two unmodulated sub-carriers as pilot bins and thereby provides two sub-carriers as a reference within each OFDM symbol. At the OFDM receiver, the two unmodulated pilot bins contain no phase information and provide a reference for the differential demodulation performed by the OFDM receiver. The OFDM transmitter operates in two modes, namely, a normal mode and a transmitter identifier information (TII) mode. The TII mode contains all of the functions of the normal mode, and also transmits a repeater identification signal with the customer data, using the inactive OFDM sub-carriers (bins). In a normal mode, the OFDM transmitter optionally fills unused (inactive) sub-carriers with zeroes and in a TII mode, the OFDM transmitter uses at least some of the unused (inactive) sub-carriers to transmit the transmitter identifier information (TII). The predefined TII value is mapped onto a set of complex symbols. The TII signal facilitates the receiver test equipment in associating the received signal with the terrestrial repeater(s) that generate the TII signal.
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公开(公告)号：DE60033209D1
公开(公告)日：2007-03-22
申请号：DE60033209
申请日：2000-02-09
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LOU HUI-LING , SAYEED ZULFIQUAR , WEERACKODY VIJITHA
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公开(公告)号：CA2317974A1
公开(公告)日：2001-03-17
申请号：CA2317974
申请日：2000-09-08
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SAYEED ZULFIQUAR , ZHENG DUNMIN , RIAZI HABIB
Abstract: A terrestrial repeater is disclosed for use in a satellite transmission syst em that may also include a plurality of satellites. The terrestrial repeaters are implemented as OFDM transmitters to minimize the channel impairments caused by multi-pat h propagation. The OFDM terrestrial repeaters differentially encode the transmitted signal over frequency, as opposed to time, in order to avoid channel phase distortion. The OFDM receiver allocates two unmodulated sub-carriers as pilot bins and there by provides two sub-carriers as a reference within each OFDM symbol. At the OFD M receiver, the two unmodulated pilot bins contain no phase information and provide a reference for the differential demodulation performed by the OFDM receiver. The OFDM transmitter operates in two modes, namely, a normal mode and a transmitter identifier information (TII) mode. The TII mode contains all of the function s of the normal mode, and also transmits a repeater identification signal with the customer data, using the inactive OFDM sub-carriers (bins). In a normal mode, the OFDM transmitter optionally fills unused (inactive) sub-carriers with zeroes and in a TII mod e, the OFDM transmitter uses at least some of the unused (inactive) sub-carriers to transmit the transmitter identifier information (TII). The predefined TII value is mapped onto a set of complex symbols. The TII signal facilitates the receiver test equipment in associating the received signal with the terrestrial repeater(s) that generate the TII signa l.
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Patent Agency Ranking
公开(公告)号：CA2289898A1
公开(公告)日：2000-06-24
申请号：CA2289898
申请日：1999-11-18
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WEERACKODY VIJITHA , SAYEED ZULFIQUAR
Abstract: A CDM satellite transmission system that broadcasts programming content, such as audio or video information, using two geo-synchronous satellites and a plurality of terrestrial repeaters based on Code Division Multiple Access (CDMA) technology is disclosed. A plurality of programming channels is multiplexed onto a carrier frequency using Code Division Multiple Access (CDMA) technology. A delayed version of the signal is transmitted with the on-time version of the programming content to accommodate uninterrupted reception in the event of a blockage. The on-time and delayed version of each information channel is transmitted by each of the satellites and repeaters, providing additional diversity gains. Thus, the satellites and terrestrial repeaters occupy the entire available bandwidth. CDM transmissions are used where the pseudo-noise sequences are the same, or linear translates of one another. The terrestrial repeaters have a direct line of sight to at least one satellite and repeat the transmission of only one satellite.
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公开(公告)号：CA2197131A1
公开(公告)日：1997-09-21
申请号：CA2197131
申请日：1997-02-10
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SAYEED ZULFIQUAR , WEERACKODY VIJITHA
Abstract: In a method and apparatus for performing adaptive hybrid automatic repeat request (ARQ) coding the coding is modified based on the acknowledgements returned by the receiver. In accordance with one illustrative embodiment of the present invention, the state of the channel is implicitly determined by the transmitter based upon the frequency of acknowledgments (ACKs and NACKs) arriving from the receiver. For example, since a NACK implies a weak received signal strength, the code rate of the FEC is advantageously reduced in response to such an acknowledgement. On the other hand, the code rate of the FEC is advantageously increased in response to an ACK. In accordance with another illustrative embodiment of the present invention, the acknowledgement returned by the receiver is modified to convey the number of errors in the corresponding received data packet. In particular, a Reed-Solomon (RS) outer code is employed in the FEC to enable the receiver to determine the number of errors in the received data packet. If the acknowledgement indicates a large number of errors at the receiver, the code rate of the FEC is advantageously reduced in response thereto.
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公开(公告)号：CA2317973C
公开(公告)日：2006-11-14
申请号：CA2317973
申请日：2000-09-08
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SAYEED ZULFIQUAR , RIAZI HABIB , ZHENG DUNMIN
Abstract: A terrestrial repeater is disclosed for use in a satellite transmission syst em that may also include a plurality of satellites. The terrestrial repeaters are implemented as OFDM transmitters to minimize the channel impairments caused by multi-pa th propagation. The OFDM terrestrial repeaters differentially encode the transmitted signal over frequency, as opposed to time, in order to avoid channel phase distortion. The OFDM receiver allocates two unmodulated sub-carriers as pilot bins and there by provides two sub-carriers as a reference within each OFDM symbol. At the OFD M receiver, the two unmodulated pilot bins contain no phase information and provide a reference for the differential demodulation performed by the OFDM receiver. The OFDM transmitter operates in two modes, namely, a normal mode and a transmitter identifier information (TII) mode. The TII mode contains all of the function s of the normal mode, and also transmits a repeater identification signal with the customer data, using the inactive OFDM sub-carriers (bins). In a normal mode, the OFDM transmitter optionally fills unused (inactive) sub-carriers with zeroes and in a TII mod e, the OFDM transmitter uses at least some of the unused (inactive) sub-carriers to transmit the transmitter identifier information (TII). The predefined TII value is mapped onto a set of complex symbols. The TII signal facilitates the receiver test equipment in associating the received signal with the terrestrial repeater(s) that generate the TII signa l.
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公开(公告)号：CA2326663A1
公开(公告)日：2001-06-16
申请号：CA2326663
申请日：2000-11-24
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RIAZI HABIB , SAYEED ZULFIQUAR , ZHENG DUNMIN
Abstract: A satellite digital audio radio system (SDARS) transmitter provides a broadcast transmission signal including a time division multiplex (TDM) mode of transmission and a coded orthogonal frequency multiplex (OFDM) mode of transmission. The SDAR S transmitter provides a transmission signal that supports four transport mechanisms or traffic channels: (1) multiple audio and data program channels (program channels), (2) a cluster control information channel (CC), (3) a global control information channel (GC), and (4) a synchronization channel (CS). In particular, the SDARS transmitter processes 100 program channels into 5 clusters, each cluster comprising GC and CS information, along with a program cluster comprising 20 program channels and CC information. The SDARS transmitter further partitions each cluster into 255 cluster segments and interleaves the cluster segments from each cluster for transmission. The SDA RS uses one identical maximal length PN (pseudo-random number) sequence as a cluster synchronization word for the five clusters. The relative phases of five cluster correlation results is used by a receiver to uniquely identify each individual cluster.
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公开(公告)号：CA2197131C
公开(公告)日：2000-05-30
申请号：CA2197131
申请日：1997-02-10
Applicant: LUCENT TECHNOLOGIES INC
Inventor： SAYEED ZULFIQUAR , WEERACKODY VIJITHA
Abstract: A method and apparatus for performing adaptive hybrid automatic repeat request (ARQ) coding in which the coding is modified based on the acknowledgements returned by the receiver. In accordance with one illustrative embodiment of the present invention, the state of the channel is implicitly determined by the transmitter based upon the frequency of acknowledgments (ACKs and NACKs) arriving from the receiver. For example, since a NACK implies a weak received signal strength, the code rate of the FEC is advantageously reduced in response to such an acknowledgement. On the other hand, the code rate of the FEC is advantageously increased in response to an ACK. In accordance with another illustrative embodiment of the present invention, the acknowledgement returned by the receiver is modified to convey the number of errors in the corresponding received data packet. In particular, a Reed-Solomon (RS) outer code is employed in the FEC to enable the receiver to determine the number of errors in the received data packet. If the acknowledgement indicates a large number of errors at the receiver, the code rate of the FEC is advantageously reduced in response thereto.
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