MULTI-ACCESS COMMUNICATION SYSTEM

A multiple access slotted wireless communication system comprising a plurality of terminals and a multi-user (or multi-access) receiver is described. The terminals and multi-user receiver communicate using a frame comprising a plurality of slots. The multi user receiver comprises a receiver for simultaneously receive m transmissions in each slot of a frame from the plurality of terminals, and a multiuser decoder for decoding the received transmissions. The multi user receiver is configured to receive one or more transmissions from one or more terminals and attempts to decode the received one or more transmissions. The multi user receiver then generates compressed broadcast acknowledgement messages and broadcasts the compressed broadcast acknowledgement messages to the one or more terminals. These may be slot based acknowledgements, indicating which slots have been acknowledged allowing terminals to determine their acknowledgement status using knowledge of which slot they transmitted in. The acknowledgement may be a hash function which hashes the terminal identifiers. Terminals can provide their terminal identifier to the received hash function to determine if they are acknowledged. These methods compress or reduce the number of bits of feedback required to send the required acknowledgements to the terminals.