公开(公告)号：DE69429037D1

公开(公告)日：2001-12-20

申请号：DE69429037

申请日：1994-07-06

Applicant: TELOGY NETWORKS INC

Inventor： BETTS WILLIAM LEWIS

IPC: H04L25/03 ,  H04L25/49 ,  H04L25/497 ,  H04L27/34

Abstract: In a system that uses a dither signal d(k) in the production or a transmitted signal, the recoverability of an original trellis code is maintained while forming the dither signal using a modulo value that is equal to the distance between two adjacent symbols. This is accomplished by forming individual modulo counts (xcnt, ycnt) for each of the orthogonal components produced by the transmitter's 3-tap FIR filter (66). The modulo counts and the bits from the trellis encoder (50) are used to substitute the constellation subset identified by the trellis encoder (50) with another constellation subset. The substituted subset is used for transmission and results in recovery of the original trellis code by the trellis decoder in the receiver.

公开(公告)号：DE69429037T2

公开(公告)日：2002-08-14

申请号：DE69429037

申请日：1994-07-06

Applicant: TELOGY NETWORKS INC

Inventor： BETTS WILLIAM LEWIS

IPC: H04L25/03 ,  H04L25/49 ,  H04L25/497 ,  H04L27/34

Abstract: In a system that uses a dither signal d(k) in the production or a transmitted signal, the recoverability of an original trellis code is maintained while forming the dither signal using a modulo value that is equal to the distance between two adjacent symbols. This is accomplished by forming individual modulo counts (xcnt, ycnt) for each of the orthogonal components produced by the transmitter's 3-tap FIR filter (66). The modulo counts and the bits from the trellis encoder (50) are used to substitute the constellation subset identified by the trellis encoder (50) with another constellation subset. The substituted subset is used for transmission and results in recovery of the original trellis code by the trellis decoder in the receiver.

公开(公告)号：EP0920762A4

公开(公告)日：2003-05-21

申请号：EP97931428

申请日：1997-06-25

Applicant: TELOGY NETWORKS INC

Inventor： BETTS WILLIAM LEWIS ,  SOUDERS KEITH ALAN

IPC: H03M13/00 ,  H04B14/04 ,  H04J3/12 ,  H04L12/00 ,  H04L25/49 ,  H04M11/06

CPC classification number: H04B14/048 ,  H04J3/125

Abstract: A compensation system (figure 2A) for improving the accuracy of digital signals that are communicated through a digital network (113, figure 1) by reducing loss from attenuation quantization (DAQ) and rob bit signaling (RBS). The combined DAQ/RBS compensation system can be employed within the transmitting modem (101) connected to the digital network. A first adjustment mechanism combines a DAQ compensation quantity with each segment of the digital data. Next, the word is communicated to a linear-mu-linear converter (201), which is configured to simulate a digital transmission by mu-low encoding each digital data word into a code word and then subsequently mu-low decoding each code word back into linear digital data word. The linear-mu-linear converter includes an RBS compensation system (129) that causes an RBS compensation quantity to be mathematically combined with each segment to be tainted by RBS. A second adjustment mechanism combines the reciprocal of the DAQ compensation quantity with the linear digital data from the linear-mu-linear converter. Finally, the linear digital data word is passed from the linear-mu-linear converter to a linear-mu-converter (208) for conversion into a mu-law code word and transmission to the network.

公开(公告)号：EP0929958A4

公开(公告)日：2003-06-04

申请号：EP97923547

申请日：1997-05-05

Applicant: TELOGY NETWORKS INC

Inventor： BETTS WILLIAM LEWIS ,  SOUDERS KEITH ALAN

IPC: H04J3/12 ,  H04Q11/04 ,  H04L25/03 ,  H04L25/49

CPC classification number: H04Q11/0421 ,  H04J3/125

Abstract: A rob bit compensation system improves the accuracy of the digital signals (112a) received from and transmitted to a digital network (113) (Figs. 1 and 4), such as a telephone network, that employs rob bit signaling (RBS) wherein the network periodically robs a bit for its own use. The system can be employed within a digital modem (101) or a codec/decoder (codec, 106), each of which is interconnected with the digital network that periodically robs a bit every nth frame, where n is, for example, 6 or 24. The system includes a compensation control utilized to detect when a Least Significant bit (LSB) of a particular frame of data consistently exhibits a certain logic state (164 and 156), either a mark (logical 1) or a space (logical 0). When an LSB of a particular frame does consistently exhibit the certain logic state, then the particular frame is considered an RBS. Furthermore, the compensation control (133) causes a quantity (e.g., one-half of an LSB) to be added or subtracted with the data corresponding with the RBS frame via a set of adders (131a and 131b) in order to enhance accuracy of the RBS frame.

公开(公告)号：EP0920750A4

公开(公告)日：2003-06-04

申请号：EP97925456

申请日：1997-05-05

Applicant: TELOGY NETWORKS INC

Inventor： BETTS WILLIAM LEWIS ,  SOUDERS KEITH ALAN

IPC: H04B14/04 ,  H04J3/12 ,  H04L25/49 ,  H04B15/00 ,  H04L1/16 ,  H04L7/00

CPC classification number: H04B14/048 ,  H04J3/125 ,  H04L25/4927

Abstract: A cooperative feedback system (210) is provided for a compensation system associated with a transmitter or codec, for enabling the compensation system to improve the accuracy of digital signals transmitted to a digital network (113). The cooperative feedback system is particularly suited for providing feedback to a compensation system (130) for correction distortion resulting from rob bits signaling (RBS), digital loss, or other types of digital signal degradation. The cooperative feedback system includes a compensation selector (204) in a transmitter (181) that combines compensations with frames of digital data by way of an addition mechanism to produce modified digital data frames. A receiver (214) is configured to receive the modified digital data frames (118b) from the digital network (113), to determine if accuracy of each of the modified digital data frames has increased based upon a corresponding compensation, and to communicate one or more quality feedback signals (118a) to the transmitter (181) via the digital network (113). The transmitter (181) receives the quality feedback signal(s) and selects and implements the compensation that yields a highest accuracy based upon the quality feedback signal(s).