It depends. An FPGA able to do that is a big one, quite expensive. Today, an even more so tomorrow, you can afford to do that kind of computations in a CPU and/or a GPU.
Regardless of who is doing the beamforming, the TX and RX analog parts are intrinsically quite expensive with at least dozen of channels.
Regardless of who is doing the beamforming, the TX and RX analog parts are intrinsically quite expensive with at least dozen of channels.