Linear Interference Cancellation for Downlink Map Reception in IEEE 802.16E

Next generation wireless systems, such as the IEEE 802.16e specification, are designed to provide great flexibility in scheduling radio resources on a per frame basis. Such flexibility, coupled with the need to maintain good quality of service (QoS) for cell-edge users can, however, lead to significant control channel overhead especially when using low code rates to maintain cell edge coverage. It is shown here that in interference-limited scenarios dual antenna mobile stations (MS) equipped with interference cancellation (IC) receivers can significantly alleviate this problem. In this study, the performance of a linear MMSE IC receiver is evaluated both at the link level and at the network level. It is shown that a practical IC receiver can achieve link performance gains in the range of 2.5-14 dB over a maximal ratio combining (MRC) receiver in single interferer dominant conditions. Performance at the network level is evaluated using the well-known EESM method to model the link-level performance for OFDM systems, and the introduction of IC receivers at the MS is shown to increase control channel coverage by 10-24% at low codeword repetition factors