Abstract: In one embodiment, the present invention includes a method for receiving channel data via a transmission channel, generating hard and soft decisions for each bit of the channel data in an equalizer, and storing the hard decisions in a first buffer and storing the soft decisions in a second buffer. Each of the soft decisions may be quantized before their storage, while the hard decisions may be generated based on a corresponding unquantized soft decision. Other embodiments are described and claimed.

Abstract: Due to code constraints and pickup limitations of optical pickups, much of the signal energy of a binary coded analog signal, and therefore much of the information content, has dissipated at frequencies above about one-half (or even above about one-fourth) of the sampling frequency fs. For example, the response of data streams from DVD layers falls off by about 40 dB by fs/4 while the response of a CD data stream falls off by about 18 dB by fs/4. Thus, a data channel is provided in which the sampling rate fs is less than the channel bit rate fb. The data channel may be part of an optical storage drive in which data has been RLL encoded at d?0 and the sampling rate may be one-half the channel bit rate. Preferably, a sequence detector is employed which outputs two channel bits for each input sample.

Abstract: A wireless communication system is provided that detects a frequency burst (FB) through analysis of the autocorrelation function of received signals. The system can accommodate the relatively large frequency offsets that are associated with less expensive reference frequency crystals. In one embodiment, the system includes FB search hardware that operates in two modes, namely an FB location mode with narrowband interference (e.g. CW or continuous wave) detection and an FB location mode without such narrowband interference detection, depending on whether a CW signal (carrier or other narrowband interferer) is present or not.

Abstract: A wireless communication system is provided that detects a frequency burst (FB) through analysis of the autocorrelation function of received signals. The system can accommodate the relatively large frequency offsets that are associated with less expensive reference frequency crystals. The system employs a multi-mode filter including an FB filter and a channelization filter. In one embodiment, the FB filter is employed until an FB is located and then, once the FB is located, the channelization filter is employed to receive signals.

Abstract: A method and system for objectively evaluating the quality of speech in a voice communication system. A plurality of speech reference vectors is first obtained based on a plurality of clean speech samples. A corrupted speech signal is received and processed to determine a plurality of distortions derived from a plurality of distortion measures based on the plurality of speech reference vectors. The plurality of distortions are processed by a non-linear neural network model to generate a subjective score representing user acceptance of the corrupted speech signal. The non-linear neural network model is first trained on clean speech samples as well as corrupted speech samples through the use of backpropagation to obtain the weights and bias terms necessary to predict subjective scores from several objective measures.