Node having an adaptive space-spectrum whitener and multi-user rake receiver for use in a cooperative broadcast multi-hop network that employs broadcast flood routing and multi-hop transmission with cooperative beamforming and adaptive space-spectrum whitening

A method performed by a node and a plurality of other nodes in a cooperative broadcast multi-hop network that employs broadcast flood routing and multi-hop transmission using a direct-sequence spread-spectrum (DSSS) waveform, the method comprising:

• receiving, at a first antenna of the node, a first plurality of DSSS signals from the other nodes on a first particular channel, and outputting a first channel that includes the first plurality of DSSS signals, wherein the first plurality of DSSS signals include transmissions that are directly received from the other nodes and multi-path components of those transmissions;
• receiving, at a second antenna of the node, a second plurality of DSSS signals from the other nodes on a second particular channel, and outputting a second channel that includes the second plurality of DSSS signals, wherein the second plurality of DSSS signals include transmissions that are directly received from the other nodes and the multi-path components of those transmissions;
• performing adaptive space-spectrum whitening (ASSW) to detect and remove interference signals received from each of the first and second channels, wherein performing ASSW comprises:
• performing a covariance analysis to generate a plurality of channelized signals comprising:
• a first channelized signal that comprises transformed beam samples for the first channel and a second channelized signal that comprises transformed beam samples for the second channel;
• receiving, at each of a plurality of modified Discrete Fourier Transform (MDFT) analysis banks each corresponding to one of the first and second antennas, a beam from one of the first and second antennas in the spectral domain, wherein each beam comprises a digitized spatial stream of frequency channelized RF samples that are digitized to preserve spatial diversity;
• channelizing the beam to generate a channelized beam of frequency samples, wherein each channelized beam comprises multiple spectral channels, wherein the channelized beams collectively comprise a number of spectral-spatial channels equal to the product of the number of channelized beams and the multiple spectral channels, wherein the channelized beams collectively form a spatial-spectral matrix (Z) of time-frequency samples across the different antennas;
• applying, at an adaptive interference mitigation space-frequency whitener module, a whitening matrix (W) to the spatial-spectral matrix (Z) to remove interference and generate an interference-mitigated whitened matrix (WZ) that comprises a plurality of interference-mitigated spatial-spectral domain channels;
• collectively re-constructing, via a plurality of MDFT synthesis banks, the interference-mitigated whitened matrix (WZ) back to a time-domain matrix (Y) that comprises a plurality of interference mitigated time-domain channelized signals, wherein each MDFT synthesis bank is configured to perform a MDFT synthesis operation on one of the spatial-spectral domain channels to generate an interference mitigated time-domain channelized signal of reconstructed beam samples, wherein each interference mitigated time-domain channelized signal represents a respective spatial channel;
• and
• combining, at a multi-user RAKE receiver when performing demodulation processing, the plurality of interference mitigated time-domain channelized signals to generate a subset (1 . . . F) of fingers that combine components of a plurality of transmissions directly received from the other nodes and multipath components of transmissions received from the other nodes.