System and method of wireless fixed access using a multiple antenna array
View Patent ↗A new method is disclosed for providing wireless fixed access from an array of service antennas to a population of local terminals. In implementations, a service transceiver station (STS) performs beamform precoding using channel state information (CSI) obtained from transmissions by the local terminals, and the STS performs power allocation using slow fading coefficients which are static over the service antenna positions and over a frequency range spanning at least some carriers used for downlink transmission.
1. A method for providing wireless fixed access between an array of service antennas and a population of local terminals, comprising:
obtaining channel state information (CSI) from transmissions by the local terminals, wherein at least some of the CSI is obtained by successive approximations using indications of signal-to-noise-and interference ratio (SINR) fed back from local terminals, the successive approximations including a first approximation of phase based on an estimate of amplitude and a second approximation of amplitude based on an estimate of phase, and wherein the CSI has fast-fading and slow-fading components between said array and said local terminals;
beamform precoding messages destined for at least some of the local terminals using the CSI;
allocating power for transmission from a multiple-antenna array to respective ones of the local terminals, wherein said allocating is performed using only slow-fading components of the CSI; and
transmitting the precoded messages to the local terminals at the allocated power levels.
2. The method of claim 1 , wherein the local terminals are user terminals having no more than local premises mobility.
3. The method of claim 1 , wherein the local terminals are wireless base stations serving user terminals, and the wireless fixed access is backhaul access for the base stations.
4. The method of claim 1 , wherein at least some of the CSI is obtained from pilot signals transmitted by the local terminals.
5. A method for providing wireless fixed access between an array of service antennas and a population of local terminals, comprising:
obtaining channel state information (CSI) from transmissions by the local terminals, wherein at least some of the CSI is obtained by successive approximations using indications of signal-to-noise-and interference ratio (SINR) fed back from local terminals, the successive approximations including a first approximation of phase based on an estimate of amplitude and a second approximation of amplitude based on an estimate of phase, and wherein the CSI has fast-fading and slow-fading components between said array and said local terminals;
allocating power for transmission of uplink messages from respective ones of the local terminals to a multiple-antenna array, wherein said allocating is performed using only slow-fading components of the CSI;
receiving the transmitted uplink messages on the multiple-antenna array; and
decoding the received messages using the CSI.
6. The method of claim 5 , wherein the decoding is performed, at least in part, by maximum ratio combining.
7. The method of claim 5 , wherein the local terminals are user terminals having no more than local premises mobility.
8. The method of claim 5 , wherein the local terminals are wireless base stations serving user terminals, and the wireless fixed access is backhaul access for the base stations.
9. The method of claim 5 , wherein at least some of the CSI is obtained from pilot signals transmitted by the local terminals.