CTH09-4: A Lattice-Reduction-Aided Soft Detector for Multiple-Input Multiple-Output Channels

Designing Soft Detectors based on Seysen's Algorithm

“…Compared with other LR-aided soft detectors, e.g., [6], [8], [11], our SA based soft detectors have several advantages. First, the complexity of the soft detectors is low, only slightly higher than that of the hard detector.…”

“…This leads to a large complexity advantage for our method over LR-aided MAP, though LR-aided MAP is claimed to have near-optimal performance when the number of candidates is large. Compared with the LR-aided soft detectors in [6], [8], our proposed soft detector avoids the huge memory storage required for the predetermined matrix D in [6, Eq. (7)].…”

“…The metric that SA uses to quantify the orthogonality of the channel matrix H is (see e.g., [3], [10]) N S(H) Z E l 2hn (6) n=1 where hn is the nth column of H and aT is the nth row of Ht. For any H, S(H) > N, with equality when H is a unitary matrix.…”

“…The LR-aided soft detector was first proposed in [11] and then improved in [6] and [8] in terms of complexity by sacrificing performance. Two more algorithms are proposed in [14] to achieve better performance while keeping the complexity low.…”

A Digital Signal Processing Architecture for Soft-Output MIMO Lattice Reduction Aided Detection

“…Bruderer et al [34]. We caution that the results in Table 3 need to be interpreted carefully, however, since it is well known that hard-output MIMO detectors such as [32], [26] and [34] do not facilitate high-performance iterative receivers involving joint detection and decoding when error-control codes such as turbo codes and LDPC codes are employed [37], [22]. The proposed approach therefore trades off increased latency for improved BER performance and the ability to readily deal with dense constellations, e.g.…”