Performance Analysis and Computational Complexity Comparison of Sequence Detection Receivers With No Explicit Channel Estimation

We consider a single-input-multiple-output (SIMO) fading channel that can be assumed static over a duration of L symbols. We show that the generalized likelihood ratio test (GLRT) receiver for detecting a block of L uncoded symbols does not require channel-state information (CSI). By deriving an exact closed-form pairwise error probability expression for the detector over slowly time-varying Rayleigh fading, we show that its performance approaches that of coherent detection with perfect CSI when L becomes large. To detect a very long sequence of S symbols over a channel that can be assumed to remain static only over L symbols, where S ≫ L, while keeping computational complexity low, we consider three pilot-based algorithms, namely, the trellis search algorithm, pilot-symbol-assisted block detection, and decision-aided block detection. We compare them with the two existing block-by-block detection algorithms, namely, lattice decoding and sphere decoding, and show the former's advantages in complexity and performance.