An optimal receiver using a time-dependent adaptive filter

The optimal time-dependent receiver (OTDR) is presented and shown to be superior to the conventional matched filter receiver when cyclostationary interference is present. This performance advantage is explained by viewing both the OTDR and the conventional matched filter receiver as time-dependent filters that use the spectral correlation properties of the signal. The matched filter is periodic at the baud rate of the signal of interest whereas the OTDR is periodic at the baud rate of the signal of interest and any other statistical periodicity of the received signal (including that of the interfering signal). These additional filter periodicities provide the OTDR with the capability of exploiting additional spectral correlation characteristics, thus providing superior performance. Simulations are presented to show the bit-error-rate performance advantage of the OTDR (a new demodulation scheme for digitally modulated signals)