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 called Chase detectors because of their resemblance to the well-known Chase algorithm for soft decoding of error-control codes. A Chase detector is fully specified by only three simple parameters; nevertheless, it reduces to a wide range of previously reported MIMO detectors as special cases, including the maximum-likelihood and decision-feedback detectors. Based on the Chase framework, we propose two new detectors, the B-Chase and L-Chase detectors, both of which perform well on fading channels. In fact, the L-Chase detector is shown to outperform the BLAST-ordered decision-feedback detector by 9.8 dB, while simultaneously requiring 17% fewer computations, on a 4-input 4-output Rayleigh-fading channel with uncoded 4-QAM inputs. Under the same conditions, the B-Chase detector falls only 0.2 dB short of the minimum-mean-squared-error sphere detector, while requiring 50% fewer computations.