Qualcomm Incorporated

Bahadir Canpolat

Farrokh Abrishamkar

Divaydeep Sikri

Raghu Narayan Challa

Zhi-Zhong Yu

Ming Yan

Awnit Kumar

Embodiments of the present invention include devices, systems and methods for prevention of dropped calls. For example, a method for wireless communication is described. A wireless communication device begins an acquisition. A scan of absolute radio frequency channel numbers for supported bands is performed using a wideband receiver. The absolute radio frequency channel numbers that include a frequency correction channel are identified. A synchronization channel is decoded using data corresponding to the identified one or more frequency correction channels. Other aspects, embodiments, and features are also claimed and described.

Enhanced GSM cell acquisition

A novel symbol estimation method produces intersymbol interference free symbols by detecting interfering symbols in an interfering channel. A channel estimate is refined for additional improvements. The method can lends itself as a serial or parallel algorithm implementation. The symbol estimation method includes using an initial estimate of received symbols and calculating a refined estimate of the received symbols using a channel estimate. The refined estimate is calculated by performing parameterization of intersymbol interference by symbols other than the symbol being refined and selecting a refined value for the symbol being refined by evaluating an optimization function. Symbol estimates are refined in multiple iterations, until a predetermined iteration termination criterion is met. Parameterization of ISI contribution of other symbols results in reduced computation by reducing total number of unknown variables in the refinement operation.

Symbol estimation methods and apparatuses

An interference cancellation receiver for a pre-coded orthogonal frequency division multiplexed (OFDM) based system combines temporal interference cancellation within the OFDM framework. Multi-path equalization and inter-symbol interference (ISI) cancellation are performed on a time domain channel estimate of a received signal. An output from the multi-path equalization is transformed to the frequency domain. Inter-channel interference (ICI) is performed in the frequency domain on an equalized signal from the multi-path equalization after transforming the equalized signal from the time domain to the frequency domain.

Advanced interference cancellation for precoded GSM edge radio access network (GERAN)

A multi-stage interference suppression receiver includes a short equalizer section configured to operate on a first portion of a received signal received over a channel to produce a first equalized signal and a first estimate of the channel, a channel estimator section configured to operate on the first equalized signal to produce a second equalized signal, the channel estimator section comprising a linear estimator and a non-linear estimator, a long equalizer section configured to operate on a second portion of the received signal to produce a first estimate of symbols in the received signal and a second estimate of the channel and an interference canceller section configured to operate on the first estimate of symbols in the received signal to generate a second estimate of symbols in the received signal based on, at least in part, the second estimate of the channel.

Multi-stage interference suppression

A signal reception method includes receiving a signal over a channel, producing a first equalized signal, a first interference suppression filter and a first estimate of the channel using a portion of a the received signal, dividing the received signal into a plurality of signal blocks, and for each one of the plurality of signal blocks, producing a second equalized signal using a portion of the first equalized signal by selecting from one of a linear estimator or a non-linear estimator and estimating symbols received in the one of the plurality of signal blocks based on the second equalized signal.

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Farnborough, United Kingdom

Bahadir Canpolat