Transposed UL-PUSC Subcarrier Allocation Technique for Channel Estimation in WiMAX

This paper introduces a new pilot pattern design for channel estimation in WiMAX. Current WiMAX systems use a subcarrier allocation technique known as Uplink Partial Usage of Subcarriers (UL-PUSC). It is based on tile structure that consists of 4 subcarriers by 3 OFDMA symbols with 4 pilots in the corners to aid the channel estimation process. We propose a new pilot pattern called “transposed ULPUSC”. It consists of 3 subcarriers by 4 OFDMA symbols. We compare between the performance of the conventional UL-PUSC and our proposed one under different radio channel conditions. We finally propose an adaptive algorithm that selects the optimum pilot pattern based on channel conditions.