Precoder-and-receiver design scheme for multi-user coordinated multi-point in LTE-A and fifth generation systems

Coordinated multi-point (CoMP) techniques can be utilised in several wireless systems, such as LTE-A and fifth generation. However, inter-user interferences (IEIs) and intra-user interferences (IAIs) may degrade the quality of service in joint transmission (JT), CoMP systems. To suppress these interferences, the authors design an interference mitigation scheme via interference alignment (IA) and channel diagonalisation (IMS-IACD), which is implemented through a local two-step precoder-and-receiver design process. First, IA is employed to force the IEIs of each user into the interfering space. Second, the IAIs of each user are effectively suppressed by channel diagonalisation with a selective method. Performance analyses show that the IMS-IACD is feasible in general JT scenarios. The IMS-IACD does not contain any iterative process and superabundant information interaction. The structure of receiver generated by the authors’ channel diagonalisation method is quite simple, so the energy consumption can be saved by using this receiver. Moreover, computational complexities of the IMS-IACD and traditional schemes are in the same order of magnitude, and simulation results illustrate that the IMS-IACD improves the bit error rates and data rates for users.