公开(公告)号：AU3322301A

公开(公告)日：2001-08-14

申请号：AU3322301

申请日：2001-02-01

Applicant: MOTOROLA INC

Inventor： MAURER PATRICK ,  KIM DAE-YOUNG ,  MEHRABANZAD SEPEHR

IPC: H04L27/00 ,  H04B7/005 ,  H04B14/04 ,  H04L25/49 ,  H04M11/00 ,  H04B14/06 ,  H04B1/38 ,  H04L5/16 ,  H04L25/34

Abstract: In a PCM modem system in which equivalence classes are used to communicate information from a transmitter to a receiver, a method is provided to solve the problem of 180° phase reversals in the communications channel which result in a garbled transmission. This is accomplished by remapping the equivalence classes into a form that can be differentially encoded and decoded such that equivalence class identity is not lost during a phase reversal of the channel.

公开(公告)号：CA2399076A1

公开(公告)日：2001-08-09

申请号：CA2399076

申请日：2001-02-01

Applicant: MOTOROLA INC

Inventor： KIM DAE-YOUNG ,  MEHRABANZAD SEPEHR ,  MAURER PATRICK

IPC: H04L27/00 ,  H04B7/005 ,  H04B14/04 ,  H04L25/49 ,  H04M11/00 ,  H04B14/06 ,  H04L5/16 ,  H04L25/34 ,  H04B1/38

Abstract: In a PCM modem system in which equivalence classes are used to communicate information from a transmitter to a receiver, a method is provided to solve the problem of 180~ phase reversals in the communications channel which resu lt in a garbled transmission. This is accomplished by remapping the equivalence classes into a form that can be differentially encoded and decoded such that equivalence class identity is not lost during a phase reversal of the channe l. Referring to Figure 2, an incoming bit stream (10) is applied to a modulus converter (12) which is in turn coupled to a mapping block (14) which maps t he output of the modulus converter to the type of structure shown in Figure 1 i n which each equivalence class is provided with a label that includes a sign b it and magnitude bits.

公开(公告)号：AU3322401A

公开(公告)日：2001-08-14

申请号：AU3322401

申请日：2001-02-01

Applicant: MOTOROLA INC

Inventor： PILOZZI JOHN ,  KIM DAE-YOUNG ,  MEHRABANZAD SEPEHR ,  MAURER PATRICK ,  LIU JACK ,  AHMED S ARIF ,  PARIZHSKY VLADIMIR

IPC: H04J3/00 ,  H04B14/04 ,  H04J3/12 ,  H04L25/49 ,  H04M7/06 ,  H03M13/25 ,  H04L23/02

Abstract: A system and method for shifting the relative phases of a PCM data frame and a network RBS frame by one or more symbols is disclosed. The method includes determining whether or not RBS is present. If RBS is present, the slots affected by RBS are identified. Next it is determined what data slots, if any, are affected by encoding. The PCM data frame is shifted so the RBS constraint and the encoding constraint do not coincide at any particular data slot. For one particular PCM upstream modulation scheme, the digital modem adjusts the relative phases of the data-mode frame and network RBS frame such that a minimum number of trellis-modified symbols fall on network RBS affected slots. This information is transmitted to an analog modem. The amount of shift can be conveyed to an analog modem in the same data sequence used to send upstream constellation sets and mapping parameters during an initial training sequence. The present invention improves the performance of any PCM modem that employs a data frame structure in which not all symbols are subject to the same constraints, for example, due to trellis coding.

公开(公告)号：CA2399513A1

公开(公告)日：2001-08-09

申请号：CA2399513

申请日：2001-02-01

Applicant: MOTOROLA INC ,  3COM CORP

Inventor： PILOZZI JOHN ,  PARIZHSKY VLADIMIR ,  MEHRABANZAD SEPEHR ,  KIM DAE-YOUNG ,  MAURER PATRICK ,  LIU JACK ,  AHMED S ARIF

IPC: H04J3/00 ,  H04B14/04 ,  H04J3/12 ,  H04L25/49 ,  H04M7/06 ,  H04L23/02 ,  H03M13/25

Abstract: A system and method for shifting the relative phases of a PCM data frame and a network RBS frame by one or more symbols is disclosed. The method includes determining whether or not RBS is present. If RBS is present, the slots affected by RBS are identified. Next it is determined what data slots, if any, are affected by encoding. The PCM data frame is shifted so the RBS constraint and the encoding constraint do not coincide at any particular data slot. For one particular PCM upstream modulation scheme, the digital modem adjusts the relative phases of the data-mode frame and network RBS frame such that a minimum number of trellis-modified symbols fall on network RBS affected slots. This information is transmitted to an analog modem. The amount of shift can be conveyed to an analog modem in the same data sequence used to send upstream constellation sets and mapping parameters during an initial training sequence. The present invention improves the performance of any PCM modem that employs a data frame structure in which not all symbols are subject to the same constraints, for example, due to trellis coding.

公开(公告)号：CA2399513C

公开(公告)日：2005-04-19

申请号：CA2399513

申请日：2001-02-01

Applicant: MOTOROLA INC ,  3COM CORP

Inventor： MAURER PATRICK ,  MEHRABANZAD SEPEHR ,  LIU JACK ,  AHMED S ARIF ,  PARIZHSKY VLADIMIR ,  KIM DAE-YOUNG ,  PILOZZI JOHN

IPC: H04J3/00 ,  H04B14/04 ,  H04J3/12 ,  H04L25/49 ,  H04M7/06 ,  H04L23/02 ,  H03M13/25

Abstract: A system and method for shifting the relative phases of a PCM data frame and a network RBS frame by one or more symbols is disclosed. The method includes determining whether or not RBS is present (100). If RBS is present, the slots affected by RBS are identifed. Next it is determined what data slots, if any, are affected by encoding (102). The PCM data frame is shifted to the RBS constraint and the encoding constraint do not coincide at any particular data slot (104). For one particular PCM upstream modulation scheme, the digital modem adjusts the relative phases of the data-mode frame and network RBS frame such that a minimum number of trellis-modified symbols fall on network RBS affected slots. This information is transmitted to an analog modem (106). The amount of shift can be conveyed to an analog modem in the same data sequence used to send upstream constellation sets and mapping parameters during an initial training sequence. The present invention improves the performance of any PCM modem that employs a data frame structure in which not all symbols are subject to the same constraints, for example, due to trellis coding.

公开(公告)号：CA2399076C

公开(公告)日：2004-10-12

申请号：CA2399076

申请日：2001-02-01

Applicant: MOTOROLA INC

Inventor： MAURER PATRICK ,  KIM DAE-YOUNG ,  MEHRABANZAD SEPEHR

IPC: H04L27/00 ,  H04B7/005 ,  H04B14/04 ,  H04L25/49 ,  H04M11/00 ,  H04B14/06 ,  H04L5/16 ,  H04L25/34 ,  H04B1/38

Abstract: In a PCM modem system in which equivalence classes are used to communicate information from a transmitter to a receiver, a method is provided to solve the problem of 180.degree. phase reversals in the communications channel which result in a garbled transmission. This is accomplished by re-mapping the equivalence classes into a form that can be differentially encoded and decoded such that equivalence class identity is not lost during a phase reversal of the channel. Referring to Figure 2, an incoming bit stream (10) is applied to a modulus converter ( 12) which is in turn coupled to a mapping block (14) which maps the output of the modulus converter to the type of structure shown in Figure 1 in which each equivalence class is provided with a label that includes a sign bit and magnitude bits.

公开(公告)号：AU2003228840A1

公开(公告)日：2003-12-22

申请号：AU2003228840

申请日：2003-05-05

Applicant: MOTOROLA INC

Inventor： SMITH PATRICK ,  BURKE TIMOTHY ,  GROSSMAN DANIEL ,  MAURER PATRICK

IPC: H04H1/00 ,  H04H60/96 ,  H04J1/00 ,  H04J14/02 ,  H04N7/173

Abstract: In a cable television system a system for supporting SCU return in FTTB-MDU and FTTC/FTTcab configurations. Fiber, baseband transceiver and networking capabilities are shared with data and voice portions of the system for enabling communication from the SCUs to the HE over a packet based networking system. Return packets/upstream packets are passed into the network upstream channel only when a signal is present for eliminating transmission of upstream traffic that contains no signal for conserving upstream bandwidth.