Effect of channel estimation error on bit rate performance of time domain equalizers

Channel equalization plays a key role in achieving high bit rates in wireline multicarrier systems. Some VDSL systems and all standardized multicarrier ADSL systems employ time domain equalization (channel shortening) and frequency domain equalization in channel equalization. In this paper, we analyze the impact of imperfect channel estimates on the bit rate performance of four time domain equalization methods. We derive a closed-form expression for the bit rate loss due to channel estimation error. We simulate the sensitivity in bit rate performance using first-generation downstream ADSL transmission. In simulation, the minimum intersymbol interference and minimum mean square error methods are relatively insensitive to channel estimation errors vs. minimum delay spread and maximum shortening signal-to-noise ratio methods.