User cooperation is an emerging transmission framework where users act as relays of each other to provide extra diversity paths for better overall performance. In various embodiments, systems and methods for transmitting data from a basestation to a mobile device in an adaptive communications network including user cooperation are provided. Among various embodiments, relaying is performed according to a time division duplex (TDD) system according to either a downlink-assisted relaying (DAR) which performs a relaying operation in a defined supplemental downlink timeslot or according to an uplink-assisted relaying (UAR) which performs a relaying operation in a defined supplemental uplink timeslot. Among other embodiments, relay transmissions according to a max-throughput scheduling algorithm which achieves a maximum system throughput without imposing any fairness constraints on users or according to a round-robin scheduling algorithm which achieves absolute fairness in terms of delays among the considered users. The downlink throughput is optimized from the basestation to the mobile device utilizing either amplify-and-forward (AF) or decode-and-forward (DF) cooperation protocols.