The Chase Family of Detection Algorithms for Multiple-Input Multiple-Output Channels

We introduce a new family of detectors for multiple-input multiple-output (MIMO) channels. These detectors are called Chase detectors because they can be interpreted as a translation of the Chase error-control decoding algorithm from time to space. The Chase detector is parameterized by only four parameters; nevertheless, it reduces to a wide range of previously reported MIMO detectors as special cases, including the maximum-likelihood and decision-feedback detectors. The Chase detector defines a simple framework for not only comparing existing MIMO detection algorithms but also proposing new ones. For example, based on the Chase framework, we propose a new detector called B-Chase that performs well on fading channels. Specifically, on a four-input four-output Rayleigh-fading channel with uncoded 16-QAM inputs, one instance of the B-Chase detector falls only 0.4 dB short of the performance of the maximum-likelihood sphere detector while reducing complexity by 68%. Another instance of the B-Chase detector outperforms the BLAST-ordered decision-feedback detector by 4.4 dB while increasing complexity by only 17%.