Punctured pilots for OFDMA communications

In this paper, we propose the punctured pilots for channel estimation in OFDMA systems. These are pilots additionally inserted, after puncturing the modulated OFDMA symbols, to enhance channel estimation performance, without lessening bandwidth efficiency. In addition, puncturing scheme of forward error correcting (FEC) codes, especially focused on LDPC codes, is also proposed to prevent the performance degradation due to the codeword bits loss caused by punctured OFDMA symbols. Simulation results show that the enhanced channel estimation induces a lower bit error rate (BER) in harsh channel environments.