Design of multiuser mimo for large antenna systems with hybrid beamforming
AssigneeFuturewei Technologis, Inc.
InventorsGuosen Yue, Bohan Zhang, Xiao-Feng Qi
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Abstract
A hybrid combination of analog RF beamforming and digital pre-coding is used to improve signal-to-noise ratio and mitigate interference as between an RF base station and a plurality of wireless receivers within a cell area of the base station. Feedback overhead for beamforming training may be reduced by using indices for identifying the preferred beams of each wireless receiver. Scheduling for channel training may be based on identifying non-colliding ones of the RF beams and assigning these to corresponding wireless receivers which can best use the assigned beams in shared transmission slots.
Claims23
A hybrid beamforming method by a base station, comprising:
- sequentially indexing through a finite set of RF output beam patterns using an analog beamforming subsystem of the base station while transmitting pilot signals;
- receiving wireless feedback reports from one or more terminals identifying at least one preferred RF output beam pattern as received by the respective feedback-providing terminal;
- assigning to one assignable transmission slot, two or more of the feedback-providing terminals for simultaneous use for forward link transmissions;
- and
- selecting different RF output beam patterns for carrying simultaneous data transmissions respectively for the two or more assigned terminals wherein the assigning of the two or more terminals to the assignable transmission slot and the selecting of the different RF output beams is based on the respective wireless feedback reports received by the base station.
A hybrid beamforming system comprising:
- a base station having a digital precoding portion and an analog RF beamforming portion;
- and
- a plurality of wireless terminals each having a respective analog RF beam tuning portion and/or a corresponding baseband digital fine tuning portion;
- wherein the base station is configured to:
- establish wireless communication with the wireless terminals using a transmission protocol having one or both of pre-assigned and assignable transmission slots;
- sequentially index through a finite set of RF output beam patterns formable by the base station using the analog beamforming portion of the base station;
- receive wireless feedback reports from one or more of the wireless terminals identifying at least one preferred RF output beam pattern received by the corresponding one or more wireless terminals;
- assign to at least one of the assignable transmission slot, two or more wireless terminals that produced the wireless feedback reports;
- and
- use two or more different RF output beam patterns for carrying out respective data transmissions for the two or more assigned terminals in the assigned at least one of the assignable transmission slots based on the respective wireless feedback reports received by the base station.
The system of claim 21 wherein each of the feedback-providing terminals has a baseband filtering section that can be tuned by way of channel training and wherein the base station (BS) has a baseband precoding section configurable to provide corresponding baseband precoding for the tuned baseband filtering sections of the respective terminals.
A mobile terminal usable in a hybrid beamforming system which establishes wireless communication between a base station and the mobile terminal while using a transmission protocol having one or both of pre-assigned and assignable transmission slots, the mobile terminal comprising:
- an analog RF beam tuning portion and a corresponding baseband digital fine tuning portion;
- and
- wherein the mobile terminal is configured to:
- receive one or more of a sequentially indexed through set of different RF output beam patterns formed by the base station;
- and
- feedback to the base station a report identifying at least a strongest one or best quality one of the received one or more RF output beam patterns.
Dependencies are inferred from the claim text.