A Novel Method to Detect the Frame-Formats in 802.11n

摘要

There are three different frame formats in standard IEEE 802.11n which are mixed format HT (high throughput), non-HT and green field HT. Two types of signal were proposed in different frame formats, HT-SIG and L-SIG. Since both L-SIG and HT-SIG are BPSK modulated, the HT-SIG is rotated by 90 degrees relative to L-SIG. The rotation allows for robust auto-detection between L-SIG and HT-SIG to differentiate varied frame formats. We proposed a novel method which employs the channel information to weigh the subcarrier detected results with high accuracy and low complexity compared to the conventional methods. The mathematical analysis and simulation results demonstrate that the proposed algorithm can achieved the nearly maximum-likelihood detection performance which is more than 10dB better than the method suggested in [4] at the differentiation error ratio of 10~(-2).