Via Technologies, Inc.

Sung-Chiao Li

Huoy Bing Lim

Ching-Chia Hsu

Tzi-Dar Chiueh

Ming-Luen Liou

Yu-Lin Wang

Chi-Yuan Peng

Chan-Shih Lin

Eric Pan

Johnson Sebeni

The invention provides a Code Division Multiple Access (CDMA) receiver for sampling a received CDMA signal into a plurality of samples. The CDMA receiver comprises a sampling control module, a code generator, and a plurality of despreaders. The sampling control module delays the samples for a plurality of different delay lengths to obtain a plurality of delayed samples respectively corresponding to each of the delay lengths, and adjusts timing of a sampling trigger signal and a code generation trigger signal according to a sampling timing adjustment signal. The code generator generates a despreading code according to the code generation trigger signal. Each of the despreaders is configured for decimating the delayed samples corresponding to each delay lengths according to the sampling trigger signal to obtain a plurality of decimated delayed samples, and despreads the decimated delayed samples with the despreading code to obtain a plurality of output signals.

Code division multiple access receiver and method for processing signals thereof

An apparatus for determining multipath correlations among a search range of input data, and a method thereof. The multipath searcher comprises a pseudo noise (PN) code generator, a correlator, and a data combiner. The PN code generator generates a first PN code corresponding to a first multipath component of the input data, postpones a first period based on the search range, then generates a second PN code corresponding to a second multipath component of the input data. The correlator is coupled to the PN code generator, and correlates the input data with the first PN code and the second PN code to produce a first correlation and a second correlation. The data combiner is coupled to the correlator, receives the first and the second correlations to determine a primary multipath component with a higher correlation thereto.

Apparatus and method for reducing complexity of matched filter

An apparatus, spread spectrum receiver, and method of controlling a circular buffer, comprising a circular buffer and a controller coupled thereto. The circular buffer receives first data at a first data rate and second data at a second data rate. The controller determines a first range in the circular buffer based on the first data rate and a first time difference between the first write and first read speed, accesses the first data in the first range, estimates a second range in the circular buffer based on the second data rate and a second time difference between the first write and first read speed, and accesses the second data in the second range, where the second range is larger than and partially covered by the first range.

Spread spectrum receiver, apparatus and method of a circular buffer for multirate data

A Viterbi/Turbo unified decoder supports both voice and data streams due to the ability of performing Viterbi (convolutional) decoding and Turbo decoding. The Viterbi/Turbo unified decoder of an embodiment reduces the hardware cost by computing path metrics for both Viterbi and Turbo decoding using a single control circuit. The control circuit comprises a plurality of processors and memory banks, and the routing rule for the processors to read/write the path metric information from/to the memory banks are fixed for both Viterbi and Turbo coded inputs.

Unified viterbi/turbo decoder for mobile communication systems

A method of path gain estimation for a downlink WCDMA system. The present invention further provides a system for realizing the path gain estimation method. A transmitting device of the system comprises a first and a second antenna to transmit signals with the space time transmit diversity (STTD) scheme. The first and second antennas transmit common pilot channel (CPICH) symbols that are orthogonal to each other, and the CPICH symbols are received by a single antenna of a receiving device. The receiving device then determines the path gain by a STTD filter coefficient determination process, which includes a block selection process for selecting a combination of the CPICH symbol and a tap gain determination process for determining equations for estimating the path gain of the system.

Method and system of path gain estimation in a WCDMA system

A method of adaptive multi-modulus equalization for an equalizer. A cost from a cost function is calculated according to a constant modulus algorithm (CMA). Equalizer coefficients are updated according to the cost, and modulus of each region is determined for a multi-modulus algorithm (MMA). The equalizer is switched to use the MMA when the cost reaches a first threshold. The MMA comprises several stages determined by thresholds, and the number of regions increases in every stage. The cost is calculated according to the MMA and modulus of each region. The equalizer coefficients are updated according to the cost, and modulus of each region is determined for the subsequent stage of the MMA. The equalizer is switched to the subsequent stage of the MMA when the MMA cost function output reaches the threshold corresponding to the current stage. The steps are repeated until the cost reaches a preset value. Then, the number of regions and equalizer coefficients are fixed to equalize the input signal.

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Taipei, Taiwan

Sung-Chiao Li