An adaptive symbol-spaced equalizer to compensate analog imperfections

Abstract

This paper presents an adaptive symbol-spaced equalizer solution to compensate for analog imperfections in a single carrier communication systems operating at very high symbol rates up to 500 Msym/s. Pass-band variations in the analog domain are typical at these high data rates, where the required bandwidth is approximately 1 GHz. Non-ideal analog filter responses and phase distortion produce Inter Symbol Interference (ISI) which increases modem implementation loss. This paper presents modeling of the modemʼs analog imperfections, an overview of the equalizer algorithm and FPGA architecture, plus analysis and simulation of the expected performance gain. Pre and post equalization results from the real time tests, including BER performance with different modulation schemes such as BPSK, QPSK and 8PSK are also shown.