Lattice sphere decoding technique for block data transmission systems

Recent years have witnessed a growing interest in demand for higher data rates for wireless communication. Decoder´s complexity of the exhaustive search decoding technique such as Maximum Likelihood Block Detection (MLBD) grows exponentially with the size of transmitted data. In this paper, a lattice sphere decoding (LSD) technique is proposed for detection in block data transmission systems (BDTS). Simulation results at 10 dB channel SNR of BDTS with LSD using block size of 20 performs are better performance as compared to previous LSD method and slightly inferior than the exhaustive search technique using the channels with spectral nulls. In term of complexity, the proposed LSD requires only 390 and 74 objective functions evaluation using radius selection based on Babai estimation (BE) and the proposed method respectively, while the exhaustive search requires 2²⁰ objective functions evaluation respectively.