Algorithm and architecture design for a low-complexity adaptive equalizer

As the need for multimedia communication continues to surge, consumers demand higher and higher transmission data rate. To circumvent the channel impairment caused by multipath fading, more and more receivers resort to adaptive equalizers. However, the complexity of time-domain adaptive equalizers can be too high for some specific applications. In this paper, a novel adaptive algorithm and its low-complexity architecture are proposed. This algorithm, called GSPT LMS algorithm, employs a new Grouped Signed Power-of-Two (GSPT) number representation. An adaptive equalizer using the proposed algorithm has been simulated and shown to be capable of equalization of 8PSK signals in several practical channels. Finally, the proposed adaptive equalizer and two other adaptive equalizers are implemented on a FPGA. Simulation results show that the proposed architecture has the lowest complexity and saves about 50% to 70% of hardware.