Achievable capacity with sequential equalizers in Rayleigh fading MIMO channels

Employing multiple antennas at both the transmitter and receiver end offers a promising channel capacity. Unfortunately equalizers, which can deliver better theoretical capacity performance usually, incur higher implementation cost. To facilitate the performance-complexity tradeoff design in practice, this paper explores the asymptotic capacity performance of sequential zero-forcing equalizers under i.i.d. Rayleigh fading channels, in terms of two measurements "capacity loss" and "capacity efficiency". Based on linear algebra and matrix operations, the capacity results are given in analytical form as functions of the coupling terms in the channel transfer function and the signal to noise ratio. The closed-form solutions enable our theoretical work serves as a reference for practical system designers.