Philip Chu Wah Yip, Age 677406 Napier Trl, Austin, TX 78729

6374375, Apr 16, 2002

May 9, 1997

08/853300

Philip C. Yip - Austin TX
Muhammad M. Rahmatullah - Austin TX
Terry L. Cole - Austin TX

Advanced Micro Devices, Inc. - Sunnyvale CA

G01R 3128

714715, 375231

A method and apparatus for allowing a modem transmitting data in the data mode to initiate retraining mode due to changing line conditions. The modem inserts a test signal within the data received from a computer system. The data and test signal are encoded and sent over a network to a second modem. The second modem compares the test signal with a standard test signal, and if the test signal received is different from the standard test signal, the second modem initiates retraining of the modems to adjust for the varying line conditions.

2005005, Mar 17, 2005

Sep 16, 2003

10/663628

Philip Yip - Austin TX, US
Paul Brown - Austin TX, US
Brian Mirkin - Austin TX, US

H04B001/38

375222000

A method for training a receiving modem is disclosed. The receiving modem can be trained by a sending modem via a four-segment training procedure. During segment training, the sending modem waits for silence on a transmission line between the sending modem and the receiving modem for 48 symbol intervals. Then, the sending modem performs segment training by sending alternating AB symbols to the receiving modem for 64 symbol intervals. During segment training, the sending modem sends CD symbols to the receiving modem for 64 symbol intervals in order to train an equalizer within the receiving modem. During segment training, the sending modem continues to train the equalizer within the receiving modem by sending scrambled binary “1” symbols to the receiving modem for 48 symbol intervals. After a successful completion of the segment training, the receiving modem can change to a data mode to begin detecting and receiving data from the sending modem.

6195782, Feb 27, 2001

May 28, 1998

9/086098

Muhammad M. Rahmatullah - Tustin CA
Tony E. Sawan - Austin TX
Philip Yip - Austin TX

Advanced Micro Devices, Inc. - Sunnyvale CA

H03M 1303

714796

A digital signal processor (DSP), hardware module, and shared memory coupled together to perform Viterbi decoding on a sequence of received symbols. Given channel coefficients, the DSP calculates initial data for Viterbi processing: combination values for each possible state and branch product values for each possible symbol. These values are stored in shared memory for access by the hardware module. The DSP further calculates the first few stages of the Viterbi processing so path metrics are well defined for every state. Path metric values are also stored into the shared memory. The hardware module is optimized to perform calculations associated with a single stage of the Viterbi algorithm. The DSP invokes by the hardware module by passing a received sample to the hardware module. The hardware module calculates a survivor state value and minimizing path metric value for each state in the state space.

6026130, Feb 15, 2000

May 9, 1997

8/853430

Muhammad M. Rahmatullah - Austin TX
Philip Yip - Austin TX
Saf Asghar - Austin TX

Advanced Micro Devices, Inc. - Sunnyvale CA

H03D 100
H04L 2714

375340

The present invention comprises a system and method for a GSM receiver to perform channel estimation under the assumption that the analog-to-digital (A/D) converter is free-running. A search process is employed, whereby the known GSM training signal is sampled with a plurality of phases which vary incrementally from zero to a full symbol period. For each phase a sample set (of the training signal) is generated. Furthermore, each sample set is used, together with the received samples, in a cross-correlation procedure to obtain a candidate impulse response vector for the transmission channel. Thus a plurality of candidate impulse response vectors are produced, one of which will be selected to be the optimal representative for the transmission channel. The optimal impulse response vector is selected as follows. Each impulse response vector is convolved with the corresponding sample set, thus producing an estimated output vector.