Minimum mean square equalization in cyclostationary and stationary interference-analysis and subscriber line calculations

Abstract

Equalization in cyclostationary interference, which occurs when similar neighboring digital communication systems cause interference (crosstalk), is considered. An expression is derived on the minimum mean square performance of a continuous-time infinite-length decision feedback equalizer in the presence of multiple cyclostationary interferers and additive white noise. This expression is calculated for a subscriber line system to show the performance improvements over the situation where the interference is stationary with the same power spectrum. Linear equalizer performance curves were also added to the comparisons. These results show two techniques which can provide opportunities for improved equalizer performance by enhancing the cyclostationarity of the interference. The first is by decreasing the misalignment of the phases of the transceiver clocks in the central office transmitters. The second is by using transmitter pulse bandwidths which are wide relative to the symbol rate