Analog MIMO detection on the basis of Belief Propagation

Abstract

Abstract-In this article we present the design of an analog detector for Multiple-Input Multiple-Output (NIMO) wireless systems, based on the well known Belief Propagation (BP) algorithm. BP has been shown to obtain excellent results when solving inference problems in sparsely connected factor graphs. Unfortunately, MIMO detection is an example of inference in a densely connected graph, so other techniques need to be applied. We show that BP in conjunction with simulated annealing can offer near optimal performance when there is enough diversity in the receiver. Interestingly, this algorithm can be easily mapped into analog circuitry, thus leading to potentially low-power area-efficient MIMO detectors. A small analog detector based on this work has been designed and laid out in a 0.25pm BiCMOS process.

Damped Belief Propagation Based Near-Optimal Equalization of Severely Delay-Spread UWB MIMO-ISI Channels

“…As in [16], comparing (17) and the joint probability distribution in a MRF given by (8), we adopt the definitions of the coupling and local field parameters as J i,j = − {R i,j } and θ i = {z i } , and the compatibility functions as…”

“…BP is a simple, yet highly effective, technique that has been successfully employed in a variety of applications including computational biology, statistical signal/image processing, etc. BP is well suited in several communication problems as well [9]; e.g., decoding of turbo codes and LDPC codes [10], [11], multiuser detection [12], [13], signal detection in ISI channels [14], [15], and MIMO detection [16], [17]. Recently, in [18], Wo and Hoeher has adopted BP for equalization in severely delayspread MIMO-ISI channels, using message passing on factor graphs.…”

Single edge based belief propagation algorithms for MIMO detection

“…Various detection algorithms have long been proposed like zero forcing (ZF), minimum mean square error (MMSE) and serial interference cancellation (SIC). In terms of BP's compatibility with other problems such as decoding and channel estimation, BP has been applied for MIMO detection recently [6]- [11]. The graph model of MIMO channels is a complete graph where each variable is connected to all the other variables, which means the graph has the most circles among the graphs having the equivalent variables.…”

“…The graph model of MIMO channels is a complete graph where each variable is connected to all the other variables, which means the graph has the most circles among the graphs having the equivalent variables. Standard BP in these complete graphs achieves poor performance [6], [7], or possesses high complexity [8]. Thereby designing message and message update rule of BP become the main issues for achieving good performance with low complexity.…”

A novel analogue circuit for controlling prosthetic hands

“…Thus it appears to be more pragmatic to process these signals in analogue domain rather than in the digital domain. Additionally, recent research shows that processing naturally occurring signals in the analogue domain may result in a significant computational advantage compared to processing them in digital domain [12,13].…”