A multiple access scheme using MSE-OFDM with reduced complexity

In this paper we propose a multiple access scheme using multi-symbol encapsulated orthogonal frequency division multiplexing (MSE-OFDM) with reduced computational complexity. MSE-OFDM is a bandwidth efficient OFDM scheme, where a number of OFDM symbols are grouped together as a frame and protected by one single cyclic prefix (CP). This improves the bandwidth efficiency and robustness of the system. However, the computational complexity is more in the equalization process in receiver for this system. We propose a multiple access scheme using MSE-OFDM, which uses a new cyclic prefix using pseudo-random (PN) sequences to reduce the computational complexity of the system. The inter-symbol interference (ISI) and the intercarrier interference (ICI) are canceled in the time domain and then frequency domain equalization can be done for each symbol independently. The signals from multiple users are assumed to be synchronous in the downlink and the channel conditions are assumed to be similar for each user.