Partial feedback scheme with an interference-aware subcarrier allocation scheme in a correlated LTE downlink

Multiple-Input Multiple-Output (MIMO) technology can increase the channel capacity and mitigate the effect of multipath fading in a wireless transmission. Orthogonal Frequency Division Multiple Access (OFDMA), however, offers high flexibility in radio resource management according to the Quality of Service (QoS) demands of different users. The combination of MIMO and OFDMA techniques, MIMO-OFDMA, has become a strong candidate for Long Term Evolution (LTE) downlink transmissions. A full feedback scheme has been known to increase the uplink overhead requirement. Therefore, a partial feedback scheme utilizing DFT-based codebook precoding is considered to exploit spatial diversity from the multiuser (MU)-MIMO. In addition, the frequency diversity will be exploited by introducing an interference-aware subcarrier allocation scheme to reduce the effect of self-interference, which occurs due to an increasing spatial correlation between the communicating MIMO antennas. A full feedback scheme is also considered in the simulation for comparison. The results have shown that the partial feedback scheme had robust Bit Error Rate (BER) performance, even when simulated in a fully correlated channel without an imposed higher feedback requirement to the base controller.