Lattice Sequential Decoding: Achievable Rates and Diversity-Multiplexing Tradeoff

In this paper, the performance limit of lattice sequential decoder for coded M× N MIMO channel is analysed. We determine the rates achievable by lattice coding and sequential decoding applied to such channel. The diversity-multiplexing trade- off under lattice sequential decoding is derived as a function of its parameter---the bias term. Such parameter is critical for controlling the amount of computations required at the decoding stage. Achieving low decoding complexity requires increasing the value of the bias term. However, this is done at the expense of losing the optimal trade- off of the channel. We show how such decoder can bridge the gap between lattice decoder and low complexity decoders [e.g., minimum mean-square error successive interference cancellation (MMSE-SIC)]. We argue that, MMSE-SIC may achieve close to the maximum diversity gain of the channel MN at very low multiplexing gain.