At&t Mobility II LLC

Cingular Wireless Ii, LLC

At&t Intellectual Property I, LP

Sbc Knowledge Ventures, L.p.

Ayman A Mostafa

Mark D Austin

Richard A Kobylinski

John Carvalho

Arunhaba Ghosh

Ramzi Barghouthi

Yiannis Argyropoulos

A system and method for interference cancellation is provided to cancel/greatly reduce the interference of a wireless network. The interferers are separated from a desired signal using independent component analysis by hypothesizing the transmitting sequence. An optional whitening filter is used after the signal separation to improve the signal conditioning. The separated signal is processed by a second pass channel estimation to improve the signal channel estimation and is fed to a Maximum Likelihood Sequence Estimation (MLSE) algorithm, such as a Viterbi algorithm, for signal detection.

Systems and methods for interference cancellation in a radio receiver system

Interference cancellation is implemented for a multiple antenna system. The multiple antenna receiver is provided that includes a whitening filter coupled to receive processed signals corresponding to signals received at respective antennas, and to generate whitened signals corresponding to each of the received signals, having a colored noise component whitened. The whitening filter coupled to determine the whitened signals, at least in part, utilizes symbols corresponding to the signals received by the plurality of antennas. A signal separator is coupled to supply the whitening filter with processed received signals having interference components reduced as compared to received signals.

Systems and methods for interference cancellation in a multiple antenna radio receiver system

A combined SAIC receiver and a multiple-antenna, receive diversity receiver are employed to reduce interference in a wireless system. The real and imaginary parts of the de-rotated signal for each receive path associated with an antenna are separately filtered and a combined output signal of all receive paths is generated. The weighting coefficients are adjusted based on an error signal produced by comparing the combined output signal with a reference signal. The weighting coefficients are initially set based on an MMSE/LS type of signal processing criteria, where the reference signal is the Training Sequence Code (TSC). Subsequent adjustment/tracking can be accomplished by using known tracking algorithms, e.g. LMS or RLS, or the coefficients can be re-computed using MMSE/LS processing. The reference signal for tracking may be a combination of the TSC and estimated data symbols provided by an equalizer.

Interference cancellation and receive diversity for single-valued modulation receivers

In a cellular communications system having a centralized radio processing portion (a base station hotel) in communication with a plurality of remote air interface radio portions (or radio heads) over a transport medium, the centralized radio processing portion compensates for a fixed delay associated with the transport medium coupling the centralized radio processing portion and one of the remote air interface radio portions when evaluating a time period corresponding to a variable delay between transmission by a mobile in communication with the one of air interface radio portions and receipt of the transmission by the centralized radio processing portion. The variable delay may relate to time out periods or time slot synchronization.

Method and apparatus to maintain network coverage when using a transport media to communicate with a remote antenna

Determining the amount of resources that needs to be provisioned for a wired backhaul link of a wireless network using a probabilistic approach that makes the determination based at least in part on the type of coding scheme selection algorithm used to encode data transmitted by the transceiver to the wireless device over the air interface of the wireless network. Because the type of coding algorithm used depends on the amount of traffic at the air interface, variations in the coding algorithms used over a given period of time can be used to accurately determine the amount of bandwidth or resources that will be required on the backhaul link. Consequently, the amount of resources that should be provisioned for the backhaul link can be accurately determined.

Method and apparatus for use in provisioning resources for a backhaul link

A Transmit Diversity Redundancy controller dynamically mediates implementation of diversity and antenna hopping by detecting and remediating faults on antenna branches while minimizing the capital investment required. The controller monitors the equipment along the antenna branches. If a fault occurs, the controller determines the appropriate fault remediation measures to implement based on default settings, or relays an indicator to an external processor (e.g., a BTS or BSC CPU) and awaits instructions. If traffic on the BTS is high, the external processor instructs the TDR controller to combine the signals carried by the downed branch with the signals carried by the active branches, and the combined carrier signals are transmitted over the active branches. Otherwise, the external processor instructs the controller to allow signals carried by the downed antenna branch to be dropped, and notifies the BSC to suspend assignment of calls to the dropped carriers until the branch is restored.

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Alpharetta, GA, United States of America

Ayman A Mostafa