Abstract: A group of nodes used for sensing in a cooperative sensing communication system (100) are selected from nodes (104-112) associated with a base station (102) operating in secondary communication mode. The group has a spatial diversity gain, as determined by a cooperative sensing index (306) that initially meets a minimum threshold. To optimize the spatial diversity gain, nodes not in the initial set are individually added to the set (408), and the index is recomputed (608). The additional node having the highest effect on spatial diversity is added to the group (614). To maintain group size, each of the original nodes is individually removed from the group (706) and the index is recomputed (708) with each initial node removed to determine which of the initial nodes provided the smallest spatial gain contribution, and is removed from the group (714).

Abstract: A method (400) and system (100) for a wireless multi-hopping communication system is provided, wherein the system (100) includes an access point (102), a source node (CR1), and a plurality of nodes. The source node (CR1) is in communication with the access point (102), and configured to transmit a signal on at least one of a plurality of frequencies. The plurality of nodes are in communication with the access point (102) and the source node (CR1), and configured to transmit a signal on at least one of the plurality of frequencies, wherein the source node (CR1) and the plurality of nodes are adapted to determine a routing path utilizing at least one intermediate node (CR2) of the plurality of nodes and a transmitting frequency of the plurality of frequencies while reducing interference to a primary user of the transmitting frequency.

Abstract: A group of nodes used for sensing in a cooperative sensing communication system (100) are selected from nodes (104-112) associated with a base station (102) operating in secondary communication mode. The group has a spatial diversity gain, as determined by a cooperative sensing index (306) that initially meets a minimum threshold. To optimize the spatial diversity gain, nodes not in the initial set are individually added to the set (408), and the index is recomputed (608). The additional node having the highest effect on spatial diversity is added to the group (614). To maintain group size, each of the original nodes is individually removed from the group (706) and the index is recomputed (708) with each initial node removed to determine which of the initial nodes provided the smallest spatial gain contribution, and is removed from the group (714).