Analysis of the multistage CM array for digital communication signals

The multistage CM array is a blind adaptive receiver that can separate cochannel digital signals. It consists of several identical stages connected in a cascade structure. Each stage is composed of a multichannel linear equalizer (MCLE) and a multichannel signal canceller (MCSC). The MCLE generates a linear estimate of one cochannel source impinging on the antenna array. This captured source is removed from the input by the MCSC, which is a parallel connection of adaptive FIR filters-one for each antenna element. We derive the Wiener weights for the MCLE and the MCSC. It is demonstrated that the power of the source captured by the first stage is reduced to the noise floor at the input of the next stage, whereas the other sources pass through essentially unchanged.