Granted Patent B2

US 7,706,323 · App. 11/743,397 · Granted Apr 27, 2010

Abstract

Claims (20)

1. In a wireless network employing Spatial Division Multiplexing Access (“SDMA”) in at least one of the cells associated with said wireless network, a method for dynamically allocating transmission resources to different subscriber devices, which method comprising the steps of:

providing at least one base station comprising at least one antenna array;

providing one or more sectors associated with said wireless communications network;

dividing one or more of said one or more sectors into a plurality of virtual sub-sectors each generated to allow communications between the base station and at least one respective subscriber;

from among said plurality of the virtual sub-sectors selecting at least one pair of subscriber devices, wherein each of the pair of subscriber devices is not interfered substantially by transmissions directed to the other subscriber of that pair;

for each of said one or more divided sectors, generating plurality of time frequency allocation maps;

transmitting said generated maps to all virtual sub-sectors associated with a respective sector of said one or more divided sectors; and

for each of said one or more sectors, beamforming the transmissions to be conveyed to the subscriber devices' pairs, summing them and conveying the summed result towards said array antenna.

2. A method according to claim 1 , wherein each of the virtual sub-sectors included in a sector is provided with a different MAC address than the remaining of the virtual sub-sectors included in said sector.

3. A method according to claim 1 , wherein if a subscriber device has a low Signal to Interference+Noise Ratio (SINR) than a pre-determined threshold, it would not be paired with any other of the subscriber devices' associated with the corresponding sector.

4. A method according to claim 1 , wherein said step of beamforming the transmissions to be conveyed to the subscriber devices' pairs, is based on a combination of the paired subscriber devices' beamforming and nulling.

5. A method according to claim 1 , wherein some of said plurality of sectors are operative by transmitting high power transmissions while other sectors are operative by transmitting low power transmissions, and wherein each of the low power transmitting sectors is generated by two adjacent antenna arrays, each associated with a high power transmitting sector and beamforming at the direction of said low power transmitting sector.

6. A method according to claim 5 , wherein the step of beamforming the transmissions to be conveyed to the subscriber devices' pairs from a high power transmitting sector comprises carrying out an SDMA process which involves transmissions associated with at least one user associated with said high power sector and two other users each associated with another sector of two low power sectors located adjacent to said high power sector.

7. A communication device for use in a wireless network employing SDMA in at least one of its cells, and operative to:

divide one or more sectors comprised in said wireless communications network into a plurality of virtual sub-sectors;

select from among said plurality of virtual sub-sectors at least one pair of subscriber devices, wherein each of the pair's subscriber devices is not interfered substantially by transmissions directed to the other subscriber of that pair;

generate and forward time and frequency allocation maps based on the selection of said at least one pair to each of the virtual sub-sectors; and

schedule transmissions destined to each of said subscriber devices so as to maximize the SDMA gain in sector throughput.

8. A method according to claim 1 , wherein said at least one pair of subscriber devices is selected so that a dot product between the antenna array signature of each subscriber device of said at least one pair of subscriber devices is lower than a pre-defined threshold.

9. A method according to claim 8 , wherein the predefined threshold is set to allow that the antenna array signature of each of said at least one pair of subscriber devices is sufficiently different from the other, in order to enable reusing the same time-frequency resources irrespective of dynamic variations in the time-frequency resources and/or in reception quality and/or in location.

Assignments (6)