Antenna Selection SFN Precoding Scheme for Downlink Cooperative MIMO Systems

Recently, there has been considerable interest in cooperative multiple-input multiple-output (MIMO) systems, where the data intended for a user equipment (UE) is simultaneously transmitted from multiple base stations (BSs). In [1], the authors investigated cooperative MIMO as a means to mitigate co-channel interference and to exploit macro-diversity for the Wyner’s model and its variants. Moreover, cooperative MIMO technologies have been adopted by 4G mobile communication standards [2]. Although the large theoretical gain in spectral efficiency promised by cooperative MIMO transmissions can be achieved by performing global precoding (GP) across multiple BSs, this approach significantly increases complexity and feedback overhead [3]. This has motivated researches into simpler precoding schemes with low feedback overhead, such as the weighted local precoding (WLP) scheme in which each BS computes its precoder based on the local channel state information [4]. In [5], we proposed a novel antenna selection single frequency network precoding scheme (AS-SFNP), in which smart antenna selection (AS) is performed at BSs and identical precoders are employed at all cooperating BSs. In this letter, we investigate the performance of several precoding schemes. For single-antenna UEs, both analytical lower bounds and simulation results are provided to show that the proposed AS-SFNP scheme and the WLP scheme achieve performance close to that of the optimal global precoding (GP) scheme in terms of average signalto-interference-plus-noise ratio (SINR). For multi-antenna