Scheduling in a wireless multi-hop relay network

A system for relaying information in a wireless relaying network having a number of network nodes, said network comprising a designated originating node, at least one relaying node, and at least two receiving nodes, wherein said system comprises:

• means, in said designated originating node, for transmitting a pilot signal;
• means, in said at least one relaying node, for receiving and forwarding said pilot signal;
• means, in each of said receiving nodes, for receiving said pilot signal and for measuring channel quality based on the received pilot signal;
• means, in at least part of said receiving nodes, for feeding back information on the measured channel quality all the way to said designated originating node;
• means, in said designated originating node, for scheduling data for transmission by selecting at least one of said receiving nodes based on received channel quality information and selecting data associated with the selected receiving node(s) for transmission;
• means, in said designated originating node, for transmitting a signal comprising said selected data and a cyclic prefix to the selected receiving node(s) via the same at least one relaying node that forwarded the pilot signal, wherein said network is based on OFDM (Orthogonal Frequency Division Multiplexing) or OFDMA (Orthogonal Frequency Division Multiple Access), and wherein said cyclic prefix is adapted to a power delay profile of an equivalent channel between the designated originating node and the selected receiving node(s) via the at least one relaying node,
• means, in said at least one relaying node, for receiving the signal transmitted by said originating node, and with a latency substantially smaller than the OFDM symbol duration, transmitting the signal in the same frequency band, such that the signal transmitted by the relaying node constructively interferes with the signal transmitted by the designated originating node when received by the selected receiving node(s).

An apparatus for use in a relaying network, said apparatus comprising:

• a transmitting module configured to transmit a pilot signal for the purpose of channel quality measurements in at least two receiving nodes, said pilot signal being received and forwarded to said receiving nodes by at least one relaying node;
• a receiving module configured to receive channel quality information from said receiving nodes;
• a multi-user diversity scheduler configured to schedule for data for transmission by selecting at least one of said receiving nodes based on said channel quality information obtained from said receiving nodes and to select data associated with the selected receiving node(s) for transmission;
• a transmitting module configured to transmit a signal comprising said selected data and a cyclic prefix to the selected receiving node(s) via said at least one relaying node, wherein said transmitting module is configured to transmit in an OFDM—(Orthogonal Frequency Division Multiplexing) or OFDMA—(Orthogonal Frequency Division Multiple Access) based network, and wherein said cyclic prefix is adapted to a power delay profile of an equivalent channel between the apparatus and the selected receiving node(s) via said at least one relaying node.