Abstract: Frequency domain based methods and systems to perform adaptive multi-mode pre-decoding linear equalization, adaptive channel estimation, turbo equalization, turbo equalization iteration control, and noise variance estimation. An adaptive linear pre-decoder equalizer may include a multi-mode equalizer, which may include a blind equalizer to determine initial equalization coefficients and a decision-directed equalizer to refine the initial equalization coefficients. Turbo equalization may include a dynamic iteration termination criterion and/or a fixed termination criterion. Turbo equalization may be based in part on an adaptive estimated noise variance. Methods and systems disclosed herein may be implemented with respect to single-carrier signals such as digital video broadcast signals.

Abstract: A mobile communication device to equalize a Doppler shifted received signal according to one embodiment is configured to: extract one or more pilot signals from a segment of the received signal; perform Minimum Mean Square Error (MMSE) filtering on the extracted pilot signals, wherein the filter provides estimated pilot signal impulse responses; estimate the amplitudes of one or more path components of the estimated pilot signal impulse responses; estimate the phases of one or more path components of the estimated pilot signal impulse responses; and combine the estimated amplitudes and the estimated phases of the path components of the pilot signal impulse responses, wherein the combination provides an estimated channel impulse response.

Abstract: Methods and systems to configure a receiver based on a channel condition. A system may be implemented to estimate a channel based on PN sequences in a received signal, concurrently equalize a frequency domain representation of the signal with multiple blind adaptive equalizers, and evaluate results of the equalizations to select coefficients of one of the equalizers for further processing. A first equalizer may implement a constant-step-size (CSS) algorithm for a static channel. A second equalizer may implement a variable-step-size (VSS) algorithm for a dynamic channel. Static and dynamic channels may be distinguished based on convergence/divergence of the equalizers, which may be determined from a mean square error estimated from PN sequences in results of the blind equalizations.

Abstract: Frequency domain based methods and systems to perform adaptive multi-mode pre-decoding linear equalization, adaptive channel estimation, turbo equalization, turbo equalization iteration control, and noise variance estimation. An adaptive linear pre-decoder equalizer may include a multi-mode equalizer, which may include a blind equalizer to determine initial equalization coefficients and a decision-directed equalizer to refine the initial equalization coefficients. Turbo equalization may include a dynamic iteration termination criterion and/or a fixed termination criterion. Turbo equalization may be based in part on an adaptive estimated noise variance. Methods and systems disclosed herein may be implemented with respect to single-carrier signals such as digital video broadcast signals.

Abstract: Methods and systems to configure a receiver based on a channel condition. A system may be implemented to estimate a channel based on PN sequences in a received signal, concurrently equalize a frequency domain representation of the signal with multiple blind adaptive equalizers, and evaluate results of the equalizations to select coefficients of one of the equalizers for further processing. A first equalizer may implement a constant-step-size (CSS) algorithm for a static channel. A second equalizer may implement a variable-step-size (VSS) algorithm for a dynamic channel. Static and dynamic channels may be distinguished based on convergence/divergence of the equalizers, which may be determined from a mean square error estimated from PN sequences in results of the blind equalizations.