| 摘要 |
For training tap coefficients of an adaptive equalizer of L taps to be used for equalizing an impulse response of a transmission channel (200) to be shorter than ~ taps, stably and speedily, a training circuit comprises: a transmitter (100) for transmitting a transmission signal (x(D)) produced by converting a frequency-domain transmission vector (X) encoded with a PRBS into a time-domain; a target-impulse-response update means (1300) for producing an updated target impulse response (B u) making use of frequency-domain division method referring to windowed tap coefficients (W W(D)), a reception signal (y(D)), and a training vector (X) encoded with a replica of the PRBS; a target-impulse-response windowing means (1400) for outputting a windowed target impulse response (B w) together with a normalization coefficient (S) by windowing and normalizing the updated target impulse response (B u) within L taps in a time-domain; a tap-coefficient update means (2500) for updating the windowed tap coefficients (W w(D)) making use of a frequency-domain LMS method referring to the normalization co-efficient (S), the windowed target impulse response (B w), the training vector (X') and the reception signal (y(D)); and a tap-coefficient windowing means (1600) for windowing the updated tap coefficients into v taps. By updating the windowed tap coefficients (W W(D)) repeatedly until a certain convergence condition is attained, the windowed tap co-efficients (W W(D)) are outputted as the tap coefficients of the adaptive equalizer.
|
