MMSE-Based MIMO Cooperative Relaying Systems: Closed-Form Designs and Outage Behavior

Abstract

In this paper, we investigate minimum mean squared error (MMSE) based amplify-and-forward cooperative multiple antenna relaying systems where a non-negligible direct link exists between the source and the destination. First, we provide a new design strategy for optimizing the relay amplifying matrix. Instead of conventional optimal design approaches resorting to an iterative gradient method, we propose a near optimal closedform solution which provides an insight. As relay systems with a direct link incur a non-convex problem in general, we exploit the decomposable property of the error covariance matrix and a relaxation technique imposing a structural constraint on the problem. Next, we study the error performance limit of the proposed scheme using diversity-multiplexing tradeoff analysis, which leads to several interesting observations on MMSEbased cooperative relaying systems. Finally, through numerical simulations, we confirm that the proposed solution shows the performance very close to the optimum with much reduced complexity and the analysis closely matches with simulation results.

Transceiver Designs for MIMO Relaying Systems with Imperfect Channel State Information

“…As expected, both schemes with perfect CSI have the lowest MSE and thus outperform the schemes with ICSI. Mobile Information Systems Figure 4 further shows that increasing channel estimation errors increasingly degrades the performance of MSE as the transceiver design is misled in the presence of ICSI, and it also con rms the fact that setting errors to zero gives the same results in [32]. e BER performance of SRD relaying systems with N t N r N d N s 4 antennas for the proposed scheme is compared with the naive AF scheme for di erent constellations.…”

Vertical Sectorization Techniques in MISO Downlink Active Antenna Systems

“…Next generations of wireless cellular networks are expected to provide higher data rates in the order of tens of Gbps [1][2][3][4] . To meet the stringent demands, directional antenna techniques have been considered as one of promising solutions [5][6][7][8][9][10][11] .…”

Performance of MIMO MC-CDMA system with channel estimation equalization and relay

“…Among these techniques, the spatial diversity is attractive, because this technique can combine with the other two diversity techniques without expansion of time and bandwidth. The MIMO technique is well verified to provide significant improvement in spectral efficiency and link reliability because of the multiplexing and diversity gains [1]. Recently, wireless relaying techniques also attracts great attention to overcome coverage limitation due to low Signal to Noise Ratio (SNR) at the cell edges, poor signal reception due to coverage holes, higher cost of increasing the number of base stations and high power requirement at mobile stations due to communicating at large distances at high speeds.…”