Abstract: A system and method for accessing elements of a table in a digital image of the table, including: obtaining the digital image of the table; finding table elements in the digital image based on digital table properties, wherein the table elements define table cells; calculating coordinates of the table cells in the digital image based on the table elements; and accessing content of a selected table cell in the digital image using the coordinates of the selected table element.

Abstract: A receiver has a sample rate converter that outputs samples of orthogonal frequency division multiplexing symbols. The receiver includes a fast Fourier transform engine that receives the samples and converts them into a plurality of frequency domain sub-carriers. A timing control circuit generates a timing error and controls the sample rate converter to adjust a sample rate of the orthogonal frequency division multiplexing symbols based at least in part on the timing error.

Abstract: In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive and convert a plurality of orthogonal frequency division multiplexing (OFDM) samples into a plurality of frequency carriers; a detector coupled to the FFT engine to determine a channel estimate for a first frequency carrier using a first channel estimate for the first frequency carrier and a plurality of other channel estimates, each of the plurality of other channel estimates for one of a plurality of neighboring frequency carriers within an evaluation window, and determine a log likelihood ratio (LLR) for the first frequency carrier using the channel estimate for the first frequency carrier; and a decoder coupled to the detector to decode a first OFDM symbol comprising the first frequency carrier using the LLR for the first frequency carrier.

Abstract: In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive and convert a plurality of orthogonal frequency division multiplexing (OFDM) samples into a plurality of frequency carriers; a detector coupled to the FFT engine to determine a channel estimate for a first frequency carrier using a first channel estimate for the first frequency carrier and a plurality of other channel estimates, each of the plurality of other channel estimates for one of a plurality of neighboring frequency carriers within an evaluation window, and determine a log likelihood ratio (LLR) for the first frequency carrier using the channel estimate for the first frequency carrier; and a decoder coupled to the detector to decode a first OFDM symbol comprising the first frequency carrier using the LLR for the first frequency carrier.

Abstract: In one aspect, an apparatus includes: a front end circuit to receive and process incoming radio frequency (RF) signals into orthogonal frequency division multiplexing (OFDM) samples; a fast Fourier transform (FFT) engine to receive and convert the OFDM samples into frequency domain sub-carriers; a demodulator to demodulate the frequency domain sub-carriers; a channel estimator to: compute a first pilot channel estimate for a first channel condition comprising a flat channel condition and a second pilot channel estimate for a second channel condition comprising a selective channel condition based on a first set of pilot sub-carriers of the frequency domain sub-carriers; and select one of the first and second pilot channel estimates using the first and second pilot channel estimate; and a control circuit to configure at least the demodulator based at least in part on the selected first or second pilot channel estimate.

Abstract: In one aspect, an apparatus includes: a front end circuit to process incoming radio frequency (RF) signals into orthogonal frequency division multiplexing (OFDM) samples of a plurality of OFDM symbols; a transform engine coupled to the front end circuit to convert the plurality of OFDM samples into a plurality of frequency domain sub-carriers; a demodulator coupled to the transform engine to demodulate the plurality of frequency domain sub-carriers; a channel estimation circuit coupled to the transform engine to determine a first channel estimate based on a first set of pilot sub-carriers of the plurality of frequency domain sub-carriers and a second channel estimate based on the first set of pilot sub-carriers; and a control circuit coupled to the channel estimation circuit to control a configuration of the demodulator based at least in part on a selected one of the channel estimates.

Abstract: In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive orthogonal frequency division multiplexing (OFDM) samples of one or more OFDM symbols and convert the one or more OFDM samples into a plurality of frequency domain carriers; and a tone cancellation circuit coupled to the FFT engine to receive the one or more OFDM samples and generate a plurality of frequency carriers for the one or more OFDM samples, identify a highest magnitude frequency carrier of the plurality of frequency carriers, and remove tone interference from the OFDM samples based at least in part on the highest magnitude frequency carrier.

Abstract: In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive and convert a plurality of orthogonal frequency division multiplexing (OFDM) samples into a plurality of frequency carriers; a detector coupled to the FFT engine to determine a channel estimate for a first frequency carrier using a first channel estimate for the first frequency carrier and a plurality of other channel estimates, each of the plurality of other channel estimates for one of a plurality of neighboring frequency carriers within an evaluation window, and determine a log likelihood ratio (LLR) for the first frequency carrier using the channel estimate for the first frequency carrier; and a decoder coupled to the detector to decode a first OFDM symbol comprising the first frequency carrier using the LLR for the first frequency carrier.

Abstract: In one aspect, an apparatus includes: a fast Fourier transform (FFT) engine to receive orthogonal frequency division multiplexing (OFDM) samples of one or more OFDM symbols and convert the one or more OFDM samples into a plurality of frequency domain carriers; and a tone cancellation circuit coupled to the FFT engine to receive the one or more OFDM samples and generate a plurality of frequency carriers for the one or more OFDM samples, identify a highest magnitude frequency carrier of the plurality of frequency carriers, and remove tone interference from the OFDM samples based at least in part on the highest magnitude frequency carrier.

Abstract: In one aspect, an apparatus includes: a front end circuit to process incoming radio frequency (RF) signals into orthogonal frequency division multiplexing (OFDM) samples of a plurality of OFDM symbols; a transform engine coupled to the front end circuit to convert the plurality of OFDM samples into a plurality of frequency domain sub-carriers; a demodulator coupled to the transform engine to demodulate the plurality of frequency domain sub-carriers; a channel estimation circuit coupled to the transform engine to determine a first channel estimate based on a first set of pilot sub-carriers of the plurality of frequency domain sub-carriers and a second channel estimate based on the first set of pilot sub-carriers; and a control circuit coupled to the channel estimation circuit to control a configuration of the demodulator based at least in part on a selected one of the channel estimates.

Abstract: In one aspect, an apparatus includes: a buffer to store orthogonal frequency division multiplexing (OFDM) samples of one or more OFDM symbols; a fast Fourier transform (FFT) engine coupled to the buffer, the FFT engine to receive the one or more OFDM samples from the buffer and convert each of the one or more OFDM samples into a plurality of frequency domain sub-carriers; and a timing control circuit coupled to the buffer. The timing control circuit may control timing based at least in part on a difference between a first correlation sum for a first portion of a cyclic prefix of a first one of the one or more OFDM symbols and a second correlation sum for a second portion of the cyclic prefix.

Abstract: The present disclosure presents a method and an apparatus for reducing cyclic redundancy check (CRC) false detections at a user equipment (UE). For example, the method may include receiving a data packet at the UE, determining whether a state metric value for each of a plurality of vector elements of a last path metric vector of the data packet is less than or equal to a first threshold, incrementing a counter when the state metric value of a vector element of the plurality of vector elements is less than or equal to the first threshold, determining whether the counter is lower than a second threshold, and providing the data packet to an upper layer protocol entity of the UE when a CRC pass for the data packet is determined and the counter is lower than the second threshold. As such, reduced CRC false detections at a UE may be achieved.

Abstract: The present disclosure presents a method and an apparatus for reducing cyclic redundancy check (CRC) false detections at a user equipment (UE). For example, the method may include receiving a data packet at the UE, determining whether a state metric value for each of a plurality of vector elements of a last path metric vector of the data packet is less than or equal to a first threshold, incrementing a counter when the state metric value of a vector element of the plurality of vector elements is less than or equal to the first threshold, determining whether the counter is lower than a second threshold, and providing the data packet to an upper layer protocol entity of the UE when a CRC pass for the data packet is determined and the counter is lower than the second threshold. As such, reduced CRC false detections at a UE may be achieved.

Abstract: A novel and useful apparatus for and method of determining the channel order and channel estimate in a communications system. The present invention is suitable for use with a wide range of channels and is particularly useful in estimating wireless channels such as GSM and other types of cellular channels. A channel estimate is performed on the entire received training sequence. Those taps having an energy larger than the energy of a channel estimation error quantity are selected for the final channel estimation model. The estimation error is calculated by dividing the complete received training sequence into two different portions, wherein both portions are of equal size. A channel estimate is used to calculate the channel estimate of both portions which are then used to calculate the channel estimation error quantity.

Abstract: An apparatus for and method of generating normalized soft decision information output from an inner decoder (i.e. equalizer) in a communications receiver. The invention is operative to normalize the soft decision information before it enters a soft outer decoder. The normalization is performed using a noise power estimate that is dynamically calculated in response to changing noise statistics on the channel. The normalized soft decision output is then applied to the soft outer decoder thus realizing maximum performance therefrom. The noise power estimate is derived from the training sequence and/or the data portion of the received signal. Both types of estimates are calculated. A binary or smoothly weighted average is calculated using both types of estimates. The weighting factor is determined based on one or more performance metrics, such as the Signal to Noise Ratio (SNR).

Abstract: A novel and useful whitening matched filter (WMF) for use in a communications receiver. The WMF is constructed by cascading a matched filter and a noise-whitening filter. The response of the matched filter is derived from the time reversed complex conjugate of the channel impulse response. The whitening filter is derived by extracting the minimum phase portion of the mixed phase channel impulse response using homomorphic deconvolution. The whitening filter is implemented using either an FIR or IIR filter adapted to process the data received before and after the training sequence using a minimum phase system in a direction in time opposite to that of the direction of corresponding data sample processing performed by the equalizer.

Abstract: A novel and useful apparatus for and method of interference reduction in a communications receiver. The invention first finds the channel estimate and the noise vector from the receive signal. An interference detector is then used to choose an appropriate compensation filter and select between adaptive and deterministic moving average models for noise prediction. After compensation filtering, a new channel estimate and noise vector is calculated. The new noise vector is used to determine noise whitening coefficients if the adaptive model is used. In the deterministic model case, the coefficients do not need to be calculated since they are already known, having been calculated a priori. The noise whitening coefficients are then used in an equalizer such as a Viterbi algorithm based equalizer.