A new spreading matrix for Block Spread OFDM

This paper presents a new spreading matrix for block spread OFDM (BSOFDM) to improve the performance of the system by increasing the correlation between the symbols. This is achieved by rotating the modulation scheme used at the transmission, say QPSK, into a higher order modulation scheme, for example 16QAM. By this the correlation between the transmitted symbols is increased. The advantage of this new spreading matrix over more traditional spreading matrices is its flexibility in achieving different higher order modulation schemes during transmission depending on the angle alpha. This is compared to other spreading matrices in frequency selective channel environment.