An apparatus comprising: a plurality of transmitting antennas (101, 103); a plurality of receiving antennas (105, 107); a plurality of wireless transmitters (111, 113) configured to transmit a respective plurality of transmit signals from a respective transmitting antenna of the plurality of transmitting antennas; a plurality of wireless receivers (115, 117) configured to receive a respective plurality of receive signals from a respective receiving antenna of the plurality of receiving antennas; a self-interference noise calculator coupled to the plurality of transmitting antennas and the plurality of receiving antennas, the self-interference noise calculator configured to generate a plurality of adjusted signals, the self-interference noise calculator comprising: a first layer of multiplication/accumulation units (MAC units) of a plurality of layers of MAC units configured to mix the plurality of transmit signals as input data and delayed versions of respective outputs of the first layer of MAC units using a plurality of coefficients to generate first intermediate processing results; and additional layers of MAC units of the plurality of layers of MAC units, each additional layer of MAC units configured to mix the first intermediate processing results and delayed versions of respective outputs of the respective additional layer of MAC units using additional coefficients of the plurality of coefficients to generate second intermediate processing results, wherein the self-interference noise calculator is configured to provide the plurality of adjusted signals as output data, the output data based partly on the second intermediate processing results; and wherein each wireless receiver is configured to receive a corresponding adjusted signal of the plurality of adjusted signals. a plurality of transmitting antennas (101, 103); a plurality of receiving antennas (105, 107); a plurality of wireless transmitters (111, 113) configured to transmit a respective plurality of transmit signals from a respective transmitting antenna of the plurality of transmitting antennas; a plurality of wireless receivers (115, 117) configured to receive a respective plurality of receive signals from a respective receiving antenna of the plurality of receiving antennas; a self-interference noise calculator coupled to the plurality of transmitting antennas and the plurality of receiving antennas, the self-interference noise calculator configured to generate a plurality of adjusted signals, the self-interference noise calculator comprising: a first layer of multiplication/accumulation units (MAC units) of a plurality of layers of MAC units configured to mix the plurality of transmit signals as input data and delayed versions of respective outputs of the first layer of MAC units using a plurality of coefficients to generate first intermediate processing results; and additional layers of MAC units of the plurality of layers of MAC units, each additional layer of MAC units configured to mix the first intermediate processing results and delayed versions of respective outputs of the respective additional layer of MAC units using additional coefficients of the plurality of coefficients to generate second intermediate processing results, wherein the self-interference noise calculator is configured to provide the plurality of adjusted signals as output data, the output data based partly on the second intermediate processing results; and a first layer of multiplication/accumulation units (MAC units) of a plurality of layers of MAC units configured to mix the plurality of transmit signals as input data and delayed versions of respective outputs of the first layer of MAC units using a plurality of coefficients to generate first intermediate processing results; and additional layers of MAC units of the plurality of layers of MAC units, each additional layer of MAC units configured to mix the first intermediate processing results and delayed versions of respective outputs of the respective additional layer of MAC units using additional coefficients of the plurality of coefficients to generate second intermediate processing results, wherein the self-interference noise calculator is configured to provide the plurality of adjusted signals as output data, the output data based partly on the second intermediate processing results; and wherein each wireless receiver is configured to receive a corresponding adjusted signal of the plurality of adjusted signals.