Markov Chain Monte Carlo MIMO Detection Methods for High Signal-to-Noise Ratio Regimes

Abstract

Abstract-Markov Chain Monte Carlo methods have recently been applied as front-end detectors in multipleinput multiple-output (MIMO) communication systems. Moreover, the near capacity behavior of such detectors in low signal-to-noise ratio (SNR) regimes have been demonstrated through computer simulations. However, it has also been found that the MCMC MIMO detectors degrade in high SNR regimes. This paper investigates into the source of this degradation and proposes a number of ad hoc methods to resolve this undesirable behavior of the MCMC MIMO detectors.

Markov Chain Monte Carlo: Applications to MIMO detection and channel equalization

“…For both ZF-C-MCMC and ML-C-MCMC, 16 constrained GSs are ran (each corresponding to a fixed bit k) with 2 iterations each. It is clear that the ZF-C-MCMC is at least one order of magnitude better than the non-constrained ZF-MCMC [5]. The ML-C-MCMC improves performance of ZF-C-MCMC at the cost of additional complexity needed to find the ML solution.…”

“…It is well-known [1], [5], [18] that MCMC methods become less effective as the operating SNR increases. This is because at higher SNRs, the Markov chain associated with the GS is likely to become reducible so that it tends to get stuck in certain states and fail to reach the states corresponding to small…”

“…This increases the chances that the GS converge to the optimal solution. In [5], it is shown that detection performance can be further improved by initializing one of the GSs using the MMSE or ZF solution. Recently, [7] proposes a constrained MCMC detector for high SNR scenarios.…”

“…As opposed to LSD detectors that perform well at high signal-to-noise ratio (SNR), the MCMC detector suffers from the high SNR problem. Possible remedies for addressing the high SNR problem of MCMC detectors can be found in recent work [5], [7].…”

“…3 we compare performance of ZF initialized MCMC (ZF-MCMC) [5], the ZF initialized constrained MCMC (ZF-C-MCMC), the ML initialized constrained MCMC (ML-C-MCMC) [7], LSD, and the exact Max-Log detector. It is assumed that MIMO detection is performed only once, followed by channel decoding.…”