Block-Wise QR-Decomposition for the Layered and Hybrid Alamouti STBC MIMO Systems: Algorithms and Hardware Architectures

Abstract

Unlike the channel matrix in the spatial division multiplexing (SDM) multiple-input multiple-output (MIMO) communication system, the equivalent channel matrix in the layered Alamouti space-time block coding (STBC) MIMO system comprised 2-by-2 Alamouti sub-blocks. One novel property, found by Sayed et al. about the QR-decomposition (QRD) of this equivalent channel matrix is that the produced -and -matrices are also matrices with Alamouti sub-blocks. Taking advantage of this property, we propose a new block-wise complex Givens rotation (BCGR) based algorithm and a triangular systolic array (TSA) to compute the QRD of the equivalent channel matrix in an Alamouti block by block manner. Implementation results reveal that our new TSA can compute QRDs of 4-by-4 equivalent channel matrices faster than any architecture that has been developed for the SDM MIMO system. This property of fast QRD makes our TSA very attractive for the layered Alamouti STBC MIMO system combined with the orthogonal frequency division multiplexing. Our new BCGR based approach can also be applied to the hybrid Alamouti STBC MIMO system, which is also a system with equivalent channel matrix consisting of Alamouti sub-blocks.Index Terms-Alamouti space-time block coding, CORDIC module, Givens rotation, multiple input multiple output system, QR-decomposition, triangular systolic array.

Givens rotation‐based QR decomposition for MIMO systems

“…The hardware complexity of our QR decomposition is lower than the design in [4]. Although the designs in [3], [6], [9], [25] have smaller gate counts than the proposed scheme, their throughputs and normalized throughputs are relatively low. Both the proposed QR Fig.…”

Analysis of the Alamouti STBC MIMO System With Spatial Division Multiplexing Over the Rayleigh Fading Channel

“…The results in (26) and (27) reveal that the entries in the upper triangular part of R are still complex Gaussian distributed. The results in (28) and (29) reveal that diagonal entries of R are chi distributed.…”

A matrix-decomposition-and-inverse-free successive interference cancelation for G-STBC systems

“…4, the BER curves for MMSE.DEC in [2], IC in [3], and QRM-MLD in [8] are also included for references. We see that the proposed SIC ( = 1) outperforms all other schemes.…”

“…It is obvious that the complexity is not desirable as the dimension of the system goes large. In the literature, some approaches were presented for detecting G-STBC systems as well to hopefully give a nice trade-off among various performance measures [4]- [8].…”