Relay multiplexing enhancement using a nonreciprocal antenna array

We introduce the concept of a nonreciprocal relay for multi-user communication in a cluttered environment. This relay is based on a nonreciprocal antenna array system that receives and transmits in different directions of space according to communication requirements. This relay features much higher gain than its conventional reciprocal and omnidirectional counterpart, where power is lost in undesired directions due to reciprocity. The proposed relay is demonstrated using in three-user downlink system design so as to receive and transmit uniquely in the appropriate directions.