A nonlinear equalization algorithm for single-carrier block transmission systems

Abstract

Combating the intersymbol interference is an important issue in single-carrier block transmission systems. In this paper, we present a nonlinear equalizer that combines frequency-domain (FD) prefiltering with time-domain tree search detection. Simulation results show that the proposed algorithm achieves a detection performance that is very close to that of the conventional tree search equalizer (which employs the QRD-M algorithm), but with a much lower complexity. In addition, the proposed algorithm performs significantly better than the linear equalizers and decision-feedback equalizers, with only a modest increase in complexity.

Hybrid-Domain Sequence Detector for Training Sequence-Aided Single-Carrier Block Transmission Signals

“…From (18), the (m, j)-th entry of U is given by [U] m,j =g H m h j , where g m and h j denote the m-th and j-th columns of G and H c , respectively. Referring to (19), for notational convenience, we further denote [U] m,j as…”

“…. , B−1 are found, the optimal U can be determined using (19); the optimal G H is thus given by G H =UH −1 c (from (18)). For practical use, a much more efficient implementation is described in Section IV-B2 and summarized in Section IV-C.…”

“…This paper is the journal version of [19]; the extension includes the following. In this paper, the same FDF-M algorithm proposed in [19] is re-formulated and re-derived using a more general framework.…”

“…In this paper, the same FDF-M algorithm proposed in [19] is re-formulated and re-derived using a more general framework. Specifically, the prefilter in this paper is designed to enforce the effective channel matrix to be a poly-diagonal matrix [16], while the effective channel matrix in [19] is designed to be circulant (which is a special case of the poly-diagonal matrix). In addition, a comprehensive characterization of detection performance and complexity is provided.…”

“…. , u m,m+1 ] T is the m-th column of U T (refer to (19)). Next, we take the following two steps to rewrite (45) as (51).…”