Abstract: 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.

Abstract: Various aspects of the present disclosure provide for an apparatus configured to receive a transmission from a serving cell utilizing a single antenna while the apparatus is operating in a first mode. While the apparatus is operating in a second mode, the apparatus may be configured to measure a signal quality of a neighbor cell utilizing at least one of two or more antennas and use receive diversity (RxD) to receive the transmission from the serving cell utilizing the two or more antennas. While the apparatus is operating in a third mode, the apparatus may be further configured to use only RxD to receive the transmission from the serving cell utilizing the two or more antennas. The first mode may be a single-antenna mode. The second mode may be a hybrid-antenna mode. The third mode may be an RxD-only mode.

Abstract: Apparatus and methods for wireless communication include receiving, in a time division synchronous code division multiple access (TD-SCDMA) network, a first number of symbols before a midamble, the midamble, and a second number of symbols after the midamble; determining first forward and backward probabilities for a first subset of the first number of symbols and second forward and backward probabilities for a second subset of the second number of symbols; determining first posterior probabilities for the first subset of the first number of symbols and second posterior probabilities for the second subset of the second number of symbols; determining a first target posterior probability and a second target posterior probability; detecting a first target symbol and a second target symbol; and determining a first channel estimate corresponding to the first target symbol and a second channel estimate corresponding to the second target symbol.

Abstract: Apparatus, methods, and computer program product for wireless communication, including receiving a plurality of chips in a time division synchronous code division multiple access (TD-SCDMA) network; performing channel matched filtering, despreading, and descrambling on the plurality of chips to determine a plurality of received symbols for each of a plurality of cells; performing symbol-level inter-cell interference cancellation on the plurality of received symbols to determine a plurality of serving cell symbol estimates; and performing multi-user detection on the plurality of serving cell symbol estimates to determine a plurality of detected serving cell symbols.

Abstract: Apparatus and methods for channel estimation in time division synchronous code division multiple access (TD-SCDMA) based on a signal received from one or more Node Bs include determining least squares channel metric estimates based on the received signal, identifying signal taps and noise taps in a tapped delay line channel estimate based on at least one of temporal correlations of the least squares channel metric estimates or composite hypothesis testing on the least squares channel metric estimates, and updating an interference buffer based on the signal taps and the noise taps.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.