A communication device can be configured to detect false positives of a decoded signal that have passed error detection. The communication device can include an error detector and a false positive detector. The error detector can detect an error of a decoded signal generated from an encoded signal, and output a payload of the decoded signal in response to the decoded signal passing the error detection. The false positive detector can calculate an estimated bit-error rate (BER) of the encoded signal and a predicted BER of the encoded signal. The false positive detector can determine a false positive of the error detection passing of the decoded signal based on the estimated BER and the predicted BER.

Systems and methods for decoding block and concatenated codes are provided, including channel state information estimation such as by using optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics, including HD Radio receivers and systems.

Techniques to increase the capacity of a W-CDMA wireless communications system. In an exemplary embodiment, early termination of one or more transport channels on a W-CDMA wireless communications link is provided. In particular, early decoding is performed on slots as they are received over the air, and techniques are described for signaling acknowledgment messages (ACK's) for one or more transport channels correctly decoded to terminate the transmission of those transport channels. The techniques may be applied to the transmission of voice signals using the adaptive multi-rate (AMR) codec. Further exemplary embodiments describe aspects to reduce the transmission power and rate of power control commands sent over the air, as well as aspects for applying tail-biting convolutional codes in the system.

Systems and methods for decoding block and concatenated codes are provided. These include advanced iterative decoding techniques based on belief propagation algorithms, with particular advantages when applied to codes having higher density parity check matrices such as iterative soft-input soft-output and list decoding of convolutional codes, Reed-Solomon codes and BCH codes. Improvements are also provided for performing channel state information estimation including the use of optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics. Particular improvements are also provided for decoding HD radio signals, satellite radio signals, digital audio broadcasting (DAB) signals, digital audio broadcasting plus (DAB+) signals, digital video broadcasting-handheld (DVB-H) signals, digital video broadcasting-terrestrial (DVB-T) signals, world space system signals, terrestrial-digital multimedia broadcasting (T-DMB) signals, and China mobile multimedia broadcasting (CMMB) signals. These and other improvements enhance the decoding of different digital signals.

Techniques to increase the capacity of a W-CDMA wireless communications system. In an exemplary embodiment, early termination (400) of one or more transport channels on a W-CDMA wireless communications link is provided. In particular, early decoding (421, 423) is performed on slots as they are received over the air, and techniques are described for signaling (431, 432) acknowledgment messages (ACK's) for one or more transport channels correctly decoded to terminate the transmission of those transport channels. The techniques may be applied to the transmission of voice signals using the adaptive multi-rate (AMR) codec. Further exemplary embodiments describe aspects to reduce the transmission power and rate of power control commands sent over the air, as well as aspects for applying tail-biting convolutional codes (1015) in the system.

A method of decoding a signal that has been encoded by a tail-biting code based on at least one encoding parameter is disclosed. The at least one encoding parameter may be a trellis size or a quantity of aggregated encoding elements or a code rate. The method is suitable for use in a communication device and comprises receiving the signal, performing a first decoding attempt of the signal based on a first set of starting state metrics and a first encoding parameter hypothesis, the first decoding attempt resulting in a first set of ending state metrics. The method further comprises performing, if the first decoding attempt fails, a second decoding attempt of the signal based on a second set of starting state metrics based on the first set of ending state metrics and a second encoding parameter hypothesis different from the first encoding parameter hypothesis.