| 摘要 |
Methods, apparatus and computer programs are provided for multiplication-free identification of the impulse response of an oversampled data channel. An input comprising a pseudo-random binary sequence of L symbols is supplied to the channel at a symbol rate of 1/T. A channel output is produced by sampling a channel output signal corresponding to the input with a sampling interval TS=(q/p)T, where q and p are relative prime integers with q<p, and q and L are relative prime integers. p polyphase sequences are produced from the channel output by selecting, for each polyphase sequence, every pth sample of the channel output, with a phase shift of one sample between successive polyphase sequences). A decimated binary sequence is produced by selecting every qth symbol of the channel input. Each polyphase sequence is correlated with the decimated binary sequence, the two possible binary values being of equal magnitude and opposite sign for the correlation. The correlation results are accumulated to produce a correlated output sequence for that polyphase sequence. The samples of the correlated output sequences are then interleaved in phase order of the corresponding polyphase sequences to produce the impulse response of the channel.
|
