Lucent Technologies Inc.

Shang-Chieh Liu

R Michael Buehrer

Steven P Nicoloso

Max Aaron Solondz

Mark David Hahm

Dirck Uptegrove

The method of channel estimation generates an initial channel estimate from a pilot signal in a received signal, and estimates the data in the received signal using the channel estimate. An updated channel estimate is then obtained from the estimated data. This process of estimating the data and re-estimating the channel estimate is reiterated a desired number of times to refine the accuracy of the channel estimate.

Iterative channel estimation and compensation based thereon

A Code Division Multiple Access system and method of operation provides reduced interference for received signals and improved signal acquisition and processing with reduced computational complexity. The system includes a base station coupled to an antenna array of at least two or more antennas and serving a plurality of users. A receiver in the base station includes a universal inverse cross-correlation matrix coupled to the antenna array, a signal acquisition and a signal processing circuit serving each user. Each signal acquisition circuit comprises a series of delay stages in which the incoming antenna signals in each stage are correlated with a spreading code and combined in a multiplier coupled to the universal inverse cross-correlation matrix which facilitates improved time delay estimation for signal acquisition. Each multiplier combines the correlated signals of the stage with the output of the universal inverse cross-correlation matrix to provide a signal amplitude representative of the signal energy in an antenna path for a given time period, with individual delays separated by a half of chip period. The amplitudes for each of the delay stages are captured in buffers which contain threshold information for selection of the strongest received signal. The signal processing circuit combines the strongest received signal with a channel estimate and the universal inverse matrix output in a multiplier to provide an output signal for demodulation and decoding with improved signal quality due to (a) reduced interference, (b) improved synchronization for signal acquisition and processing, and (c) the universal inverse cross-correlation matrix reducing computational complexity in signal acquisition and signal processing.

Code division multiple access system and method of operation with improved signal acquisition and processing

The method of channel estimation determines linear regression coefficients for N blocks of a first signal component in a received signal on a block-by-block basis, and determines a channel estimate based on the linear regression coefficients for the N blocks. Using the channel estimate, channel distortion in a second signal component of the received signal can be significantly eliminated.

Method of channel estimation and compensation based thereon

An apparatus and method of adaptive sectorization that is amiable to CDMA environments using an antenna configuration and a phase shifter network that can form a variable width beam over which a pilot signal and other downlink signals may be transmitted. The antenna configuration having at least an antenna sub-array with two or more antenna elements. The phase shifter network having a plurality of switches for adjusting beam width by directing signals to be transmitted over one or more of the antenna elements, and phase shifters for shifting phases of the signals to be transmitted over the one or more antenna elements.

Variable sectorization tower top applique for base stations

The base station system includes a cancellation processor connected to a plurality of conventional signal processors. Under the control of a controller, the signal processors acquire user signals in signals received by the base station antennas. The controller controls the cancellation processor to perform cancellation operations with respect to the acquired user signals. The cancellation processor includes first-nth filter stages. Each filter stage operates in the same manner. A filter stage obtains, in parallel, the acquired user signals from signals supplied thereto by estimating symbols in the acquired user signals under the control of the controller. The cancellation processor also includes a cancellation stage associated with each filter stage. Each cancellation stage cancels, in parallel, the obtained user signals output from the associated filter stage from the signals received by the base station antennas. The resulting residual signals output from a cancellation stage are supplied to the next filter stage, and the signals supplied to the first filter stage are the signals received by the base station antennas. A cancellation stage cancels the obtained user signals received thereby from the received signals at a substantially same time with respect to the received signals.

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Dover, NJ, United States of America

Shang-Chieh Liu