A spatial interpolation algorithm for the upsampling of uniform linear arrays

A method to spatially interpolate (upsample) a uniform linear array (ULA) originally sampled at less than the spatial Nyquist rate in the presence of noise is considered. The multichannel narrowband interpolation algorithm is based on a forward-backward linear prediction approach. The method interpolates N-1 virtual sensor outputs based on the outputs of N real sensors. This is done by solving a set of forward-backward linear prediction equations that relate the known (real) sensor outputs to the unknown (virtual) sensor outputs. Simulation results that validate the performance and usefulness of this method are presented in the context of code division multiple access (CDMA) mobile communications. The algorithm is applied to increase the user capacity and resolution and decrease the mutual coupling of ULA´s used in conjunction with cellular CDMA systems