Improvement of multiple antennas diversity systems through receiver nonlinear coupling cancellation

In order to gain diversity and achieve high bit rates, the recent trends in mobile communication industry include the use of multiple antennas in transmitter and at the receiver. As the mobile terminals get smaller, the number of electronic elements inside of them rises and the electronic interferences, like RF coupling, emerge. In this contribution, the coupling is modeled with polynomials limited to third order nonlinear behavior. To combat the multi antenna RF front-end coupling the software module at the output of AD converter is proposed. Inside the module, signal enhancement is achieved based on the inverse nonlinear coupling function of the 9th degree. The inverse function is solved using simulated annealing (SA) approximation method. The proposed coupling cancellation algorithm is analyzed under different system conditions showing excellent coupling cancellation characteristics.