Performance enhancement of space-time constant modulus array for smart antenna applications

Co-channel interference (CCI) and inter-symbol interference (ISI) are major factors causing performance degradation in mobile communications. The space-time constant modulus algorithm (STCMA), which performs both spatial and temporal filtering, has shown its effectiveness in combating both ISI and CCI. However STCMA convergence is sensitive to coefficient initialisation and interference scenario. Two methods are proposed here to improve the weight initialisation and relax the interference scenario. In one particular approach, the antenna array is utilised to provide preliminary spatial discrimination, hence obtaining flexibility in initialisation. Simulations demonstrate that both residue error power and convergence speed are improved by both methods.