Abstract: A method and apparatus for cooperative relaying in wireless communications is provided. An efficient and simplified relay scheme is disclosed that transitions between different modes on a per packet basis using scheduling information or switching information included in the packet, without requiring link reconfiguration. The cooperative relay scheme benefits further from the use of cooperative relaying protocols that emphasize centralized scheduling. One protocol emphasizes physical layer cooperation via synchronized transmissions and distributed space-time coding and the other protocol emphasizes medium access control (MAC) layer cooperation using different MAC flows or messages.

Abstract: A method for network coding of packets between End Nodes (ENs) and a Relay Node (RN) in wireless communications can be performed at the RN. This method may include: receiving a new packet at the RN from one of the ENs; determining the source node of the new packet at the RN; providing a buffer for each EN; determining whether the buffer associated with the EN that is not the source of the new packet (non-source buffer) has the new packet buffered and based upon such determination, either: (1) storing the new packet in the EN buffer that is the source of the new packet on a condition that the non-source buffer is empty; or (2) network coding the new packet with an existing packet in the non-source buffer.

Abstract: A wireless communication method and apparatus are disclosed for assigning different phases, (i.e., time periods), to perform data transmissions over designated frequency bands in a cooperative relaying system. In phase 1, a relay station (RS) listens to a wireless transmit/receive unit (WTRU) and successfully receives b information bits. In phase 2, the RS and WTRU cooperatively transmit these b information bits to the destination. These transmissions may be performed in a unicast scheme, wherein a WTRU sends information to a selected RS in phase 1, and the RS forwards the information to a base station (BS) in phase 2. The transmission may also be performed in a multicast scheme, wherein the WTRU sends information to the RS and the BS in phase 1, and the RS transmits a subset the information to the BS in phase 2.

Abstract: A method and apparatus are used in cooperative relays with incremental redundancy (IR) and distributed spatial multiplexing. A wireless transmit/receive unit (WTRU) may listen to the base station (BS) transmission during Phase 1 of the communication, and use cooperation between a relay station (RS) and the BS for the data transmission during Phase 2 to improve performance. During Phase 2, both the BS and the RS may transmit data to the WTRU, using either distributed Space Time Block Codes/Space Frequency Block Codes (STBC/SFBC) or distributed spatial multiplexing.

Abstract: A method and apparatus for cooperation in wireless communications. Cooperation is considered among a number of network elements, including at least one wireless transmit-receive unit, at least one relay station, and at least one base station.