Since there is a great demand for fast and reliable wireless transmission there is a need to extend the standardization limit of WLAN standards. In the existing solution the main focus is on the security and offered throughput. This paper mainly deals with the steganographic channels in high speed 802.11n networks. Here the modification of cyclic prefix in OFDM has been discussed. This is the highest hidden transmission technique known till date. Here the main focus is on the theoretical analysis and simulation results of the steganographic system performance.