Motorola Corporation

Alexandre Mallette

John Paul Oliver

Christopher P Larosa

Bryan W Zancho

Mymy Nguyen

A method and apparatus for channel estimation in a rake receiver of a CDMA communication system operates with a finite-impulse-response channel estimation filter with L taps and having a fixed delay. A pilot sequence of a received sequence of data from a channel of the communication system on the rake receiver is input. A quality of the channel of the communication system is determined using noise or Doppler measurements. These measurements are used in adjusting a bandwidth of the filter to accommodate the channel quality while keeping the fixed delay, which minimizes the delay buffer size. The filter is then used to operate on the received sequence of data to provide coherent modulation.

Channel estimation in a rake receiver of a CDMA communication system

A method in a code division multiple access communication system having network infrastructure and a plurality of mobile terminals, including transmitting ( ) composite signal comprising a synchronization signal and another non-orthogonal signal from the network infrastructure, receiving ( ) the composite signal at the plurality of mobile terminals of the code division multiple access communication system, and increasing forward link capacity of the code division multiple access communication system by canceling ( ) the synchronization signal from at least some of the plurality of mobile terminals.

Methods and communications terminals for increasing capacity CDMA communications networks

A method for estimating Doppler spread in mobile wireless communication devices, for example in CDMA or W-CDMA cellular communication systems, with improved noise immunity. The Doppler spread estimation is based on an estimated value of an autocorrelation or autocovariance at a first lag ( ) and at a second lag ( ), the magnitude of which is greater than the first lag. A first ratio is determined ( ) between a first difference ( ) and a second difference ( ). The estimated Doppler spread is generally proportional to a square root ( ) of the first ratio, and is scaled ( ) by a multiplicative factor that depends on whether the estimated function is an autocorrelation or autocovariance function.

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Chicago, IL, United States of America

Alexandre Mallette