linearprecoding (LP) techniques for a multiuser multiple-input-multiple-output broadcast channel is investigated and analytical results of the achievable sum capacity and error performance for zero forcing (ZF) linea...
详细信息
linearprecoding (LP) techniques for a multiuser multiple-input-multiple-output broadcast channel is investigated and analytical results of the achievable sum capacity and error performance for zero forcing (ZF) linear precoders is presented. It is shown that the detection signal-to-noise ratio of ZF-LP can be accurately approximated by a shrinking Chi-square distribution. The symbol error rate and its achievable diversity gain of ZF-LP are given. Then, an improved linear precoder based on the minimum mean-square error (MMSE) criterion is derived. Its error performance and sum capacity are analysed and compared with that of the ZF-LP. It is shown that the MMSE-LP can achieve much better error performance and a high sum capacity than the existing ZF-LP.
Spectral efficiency, energy efficiency, and security are cornerstones for the upcoming 5G systems. In this study, the issue of how the energy and spectral efficiency of multiuser massive multiple-input multiple-output...
详细信息
Spectral efficiency, energy efficiency, and security are cornerstones for the upcoming 5G systems. In this study, the issue of how the energy and spectral efficiency of multiuser massive multiple-input multiple-output (Ma-MIMO) systems are affected in the presence of a secrecy constraint is addressed. The performance of the two most prominent linear precoding techniques, the matched filter (MF) and zero-forcing (ZF) precoders, for secure downlink multiuser Ma-MIMO in the presence of multi-antenna passive eavesdropper is investigated. The authors consider three performance metrics, namely, the achievable ergodic secrecy rate, the secrecy spectral efficiency (SSE), and the secrecy energy efficiency (SEE), assuming perfect and imperfect channel state information. The tradeoff between SSE and SEE is also studied. Moreover, the authors derive tight lower bounds on the achievable ergodic secrecy rate for MF and ZF precodingtechniques. The derived lower bounds provide insights on the tradeoff between the SSE and SEE. It is shown that ZF precoder outperforms MF precoder at high transmit power, whereas at very low transmit power, MF outperforms ZF. Moreover, it is shown that using large number of transmit antennas can improve the SSE and the SEE with orders of magnitude compared to a single-input single-output system.
In the last few years, huge interest has been directed towards research in wireless communications technology, notably at the level of the recently born massive MIMO systems. In such systems, the function of precoding...
详细信息
In the last few years, huge interest has been directed towards research in wireless communications technology, notably at the level of the recently born massive MIMO systems. In such systems, the function of precoding at the base station (BS) plays a central goal in guaranteeing reliable downlink transmission. This paper aims to suggest a new low complexity linearprecoding algorithm that can provide enhanced performance for downlink mm-wave massive MIMO systems. For this end, a first iterative solution is briefly computed by the Jacobi (Jac) method and then provided as an initialization for the known iterative symmetric successive over relaxation (SSOR) algorithm. This developed iterative way reduces the complexity by one order of magnitude compared with that of the zero forcing (ZF) near-optimal precoding, which relies on direct calculation of a large inverse matrix. In addition, to prove the performance of the new proposed Jac-SSOR iterative algorithm compared with its origin versions, some benchmarking simulations have been carried out in adequate typical scenario.
暂无评论