BER Performance Enhancement of MIMO Systems Using Hybrid Detection Techniques Based on Sphere Decoding

MIMO system is used in new communication systems to improve the bit error rate (BER), capacity, and the co-channel interference. In this paper, new hybrid detection techniques based on a combination between the sphere decoder (SD) and linear/non-linear detection techniques such as zero forcing (ZF), minimum mean square error (MMSE), Vertical Bell Lab Layered Space Time (V-BLAST), and lattice reduction are introduced. These hybrid techniques are intended to improve the BER performance of MIMO system. The proposed techniques are mainly based on dividing the received signal matrix into two equal size halves. The first half of the received symbols is detected using the selected linear or non-linear detector and the second half is detected using SD as the first scenario. For the second scenario, the first half of the received symbols is detected using SD and the second half is detected using the selected linear or non-linear detector. Several simulations are carried out to verify the efficiency of the proposed techniques. The simulations results show that the proposed techniques provide better performance than the traditional ones.