Abstract: A television signal processing apparatus comprising a receiver comprises a distortion estimator and an automatic gain control signal generator. The automatic gain control signal generator generates a plurality of automatic gain control and filter response control signals in response to the magnitude or signal to noise ratio of an RF signal and a non-linear distortion figure generated from the information carried by said RF signal. The distortion estimator uses a plurality of statistical methods to generate a non-linear distortion figure from the signal constellation of the information carried by said RF signal.

Abstract: An Orthogonal Frequency Division Multiplexing (OFDM) receiver that employs N second-order phase-lock loops sharing a common integrator (where N is the number of pilots in the system). The N second order phase-lock loops track out independent pilot phase rotations to facilitate the constructive averaging of the pilots' phase information. At the same time, by sharing a common integrator, the OFDM receiver takes advantage of noise averaging over multiple pilots to obtain a cleaner frequency offset estimation. The OFDM receiver may also compensate for FFT window drift by calculating a phase difference between a selected pair of pilots and tracking the rate of change of the calculated phase difference over time. The calculated phase difference is used to control the position of an upstream FFT window after a predetermined phase difference threshold is exceeded. The tracked rate of change is used to continuously adjust the phase of downstream equalizer taps.

Abstract: The disclosed embodiments relate to exploiting circuitry that exists in a typical Orthogonal Frequency Division Multiplexing (OFDM) receiver to find the phase of a complex number corresponding to an input signal without implementing additional costly circuitry or employing a relatively slow inverse tangent look-up table. The magnitude of the complex number is normalized and processed through a closed loop to produce an output proportional to the phase of the complex number.

Abstract: The disclosed embodiments relate to a centralized buffer architecture for an Orthogonal Frequency Division Multiplexing (OFDM) receiver. In this architecture, a central buffer is shared by the main functional blocks or modules of the OFDM receiver. A state machine enables access to the buffer by the functional blocks to maintain buffer coherency.

Abstract: A television signal processing apparatus comprising a receiver comprises a distortion estimator and an automatic gain control signal generator. The automatic gain control signal generator generates a plurality of automatic gain control and filter response control signals in response to the magnitude or signal to noise ratio of an RF signal and a non-linear distortion figure generated from the information carried by said RF signal. The distortion estimator uses a plurality of statistical methods to generate a non-linear distortion figure from the signal constellation of the information carried by said RF signal.

Abstract: The disclosed embodiments relate to a technique for selecting one of several antennas or channels in a receiver based on the quality of the channel response at each of the antennas in a multicarrier system employing convolutional forward error-correction coding. Channel estimates are computed for each subcarrier and monotonic weights are assigned to each subcarrier based on the relative strength of the channel response for that subcarrier. The monotonic weights are mapped to each bit in a symbol for each subcarrier and bits are de-interleaved, if needed. A sliding window evaluation is performed to determine an overall channel quality metric for each channel. The antenna or channel having the highest overall CQM is selected to receive data.

Abstract: The present invention concerns a digital signal tuning apparatus which includes an offset frequency correction system. In the offset frequency correction system, searching for an offset signal starts from an end point of a band of frequencies in which the offset signal may be found.