Partially orthogonal SLM in SISO OFDM system without side information

A novel technique, namely partially orthogonal selected mapping (POSLM), is proposed. Instead of generating full random (or full orthogonal) independent SLM vectors, part of each vector is generated randomly, while the remaining part is generated from an orthogonal set (such as Walsh-Hadamard), hence a smaller size of the Walsh-Hadamard matrix than that of Orthogonal SLMs, is produced. As a result, such a method guarantees non-requirement of the algorithm mentioned for OSLM design. Consequently, the production of partially-orthogonal candidate vectors guarantees satisfactorily low complexity of recovery to identify the desired vector without side information, while maintaining a comparable PAPR reduction and BER performance.