Layered Detection and Decoding in MIMO Wireless Systems

Iterative detection and decoding (IDD) in multiple-input multiple-output (MIMO) wireless systems is known to achieve near channel capacity. The high computational complexity of IDD, however, poses significant challenges for practical implementations (in terms of circuit area, latency, throughput, and power consumption). While the implementation of the involved detector and decoder circuits have received considerable attention in the literature, only little is known about the efficient combination of both blocks in an IDD architecture. In this paper, we propose a novel iterative receiver schedule, which simultaneously performs detection and decoding on the same code block. This novel IDD approach is referred to as layered detection and decoding (LDD) and achieves lower latency and better performance compared to conventional solutions. Moreover, LDD is able to automatically match the decoding effort to the wide range of different modulation schemes and code rates specified in modern MIMO wireless standards. To demonstrate the advantages of LDD, we present an extensive case study based on the characteristics of existing reference designs of a soft-input soft-output MMSE detector and an LDPC decoder.