Method and apparatus for medium access control in a wireless broadband system with multiple-input multiple-output or multiple-input single-output technology with multiuser capabilities

摘要

Method and apparatus for medium access control in a wireless broadband system with multiuser MIMO/MISO technology comprising the steps of a transmitter (Tx) broadcasting a polling message (1) to all the users (Rx1 . . . Rxi . . . RXN) associated to said transmitter (Tx); the users answering with reply messages (2) during a time slot (61 . . . 6m) randomly selected from a plurality of time slots in which a period of time dedicated to sending reply messages (5) is divided; the transmitter (Tx) performing a scheduling and transmission of data (3); and scheduled users sending Acknowledgment messages (4). Preferably, only users which measure a Signal to Noise plus Interference Ratio over a pre-defined threshold for a transmission beam send reply messages (2).

主权项

1. A method for Medium Access Control in a wireless broadband system with Multiple-Input Multiple-Output or Multiple-Input Single-Output technology with multiuser capabilities, the method comprising:
(i) creating, by means of a plurality of antennas comprised by a transmitter, a plurality of transmission beams which are multiplexed in space; (ii) broadcasting from the transmitter to a plurality of users through every transmission beam a polling message which requests a state information of, at least, one transmission beam, said polling message includes a length of a period of time dedicated to sending reply messages; (iii) measuring a signal to noise plus interference ratio for each transmission beam at each user; (iv) sending a reply message from at least one user which receives the polling message, wherein the reply message comprises, at least, a first field which indicates the highest signal to noise plus interference ratio measured by the user among the transmission beams and a second field which indicates an identifier of the transmission beam for which the highest signal to noise plus interference ratio is measured at the user; and wherein the reply message is sent during a time slot randomly selected from a plurality of time slots in which a period of time dedicated to sending reply messages is divided; (v) at the transmitter, assigning a user and a transmission bit rate to each transmission beam according to the signal to noise plus interference ratio measured by the assigned user for said transmission beam; (vi) simultaneously sending data from a transmission queue to each assigned user at the assigned transmission bit rate over the plurality of transmission beams; and (vii) sending an Acknowledgement message to the transmitter from each user which successfully receives data from the transmission queue sent by the transmitter.