Abstract: A wireless communication unit includes a transmitter for processing a baseband transmit signal to produce a first radio frequency signal. A receiver is arranged to convert a second radio frequency signal to a baseband receive signal, where the receiver has a summation module arranged to add a cancellation signal to the baseband receive signal. A selectivity element is arranged to couple the transmitter and the receiver to an antenna, where a reduced portion of the first radio frequency signal is introduced into the second radio frequency signal thereby creating a second order inter-modulation distortion component in the baseband receive signal. An adaptive estimator module has a filter for filtering the baseband receive signal to remove dc offsets associated with the second order inter-modulation distortion component and generate the cancellation signal based on the baseband transmit signal and the filtered baseband receive signal for inputting to the summation module.

Abstract: A method of operating a receiver to determine a bad frame indication (BFI) of a received speech block includes decoding speech information bits of the received speech block; re-encoding the decoded speech information bits; comparing the received speech information bits with the corresponding decoded and re-encoded speech information bits to calculate a number of erroneous bits; determining a mode information of the received speech block; calculating a signal quality measurement of the received speech block; calculating a block quality metric according to the mode information, wherein the block quality metric is related to both the number of erroneous bits and the signal quality measurement; and setting the BFI of the received speech block according to the block quality metric.