Layered Space-Frequency Detection for MIMO-CDMA Systems Using Virtual Antennas

This paper proposes a new approach to apply fractionally spaced frequency-domain equalizer (FSFDE) for the single carrier MIMO-CDMA systems. The complexity of this equalizer can be significantly reduced with the help of performing the equalization in the frequency domain. Analogous to the previously developed layered space-time architectures, we proposed layered space-frequency detection (LSFD) which is performed layer by layer in a successive way. In this work, the concept of virtual antennas is also introduced. Oversampling at the receiver is equivalent to having multiple virtual receive antennas with the correlated channel gains and the colored noise. This may be viewed as a virtual receive diversity, and therefore, each polyphase component is denoted as a virtual antenna. Simulations demonstrate that high performance can be achieved by using the proposed detection with virtual antennas.