BEAMFORMING IN A MU-MIMO WIRELESS COMMUNICATION SYSTEM WITH RELAYS

• US 20180234157A1
• Filed: 01/28/2018
• Published: 08/16/2018
• Est. Priority Date: 01/16/2015
• Status: Active Grant

• Current Assignee: RF DSP, Inc.
• Original Assignee: RF DSP, Inc.
• Inventors: Liang, Ping, Zhu, Dengkui, Li, Boyu, Ma, Yiming
• Granted Patent: US 10,797,776 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04B 7/15507 Relay station based processing for cell extension or control of coverage area, network planning with network coordinated processing with regard to cell extension H04W16/26; network topologies using dedicated repeater stations H04W84/047; terminal devices adapted for relaying to or from an other terminal H04W88/04
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

This invention presents methods for MU-MIMO wireless communication systems comprising a BS with plural of antennas, either closely located or distributed; A plural of AFRs deployed over a coverage area, each AFR has N_BF≥1 BF antennas with a beam pattern facing the MU-BFer and N_UF≥1 UF antennas with a beam pattern facing UEs or downstream AFR(s); A channel estimation module for estimating the Total Channels between a plural of UEs and the BS with the AFRs in place; and, A MU-BFer that uses the estimates of the Total Channels to perform beamforming computations for transmitting and/or receiving multiple spatially multiplexed streams of signals to or from a plural of UEs using the same frequency resource.

Claims

1-34. -34. (canceled)

35. A method for Multiple-Input-Multiple-Output (MIMO) communication comprising

estimating total channel parameters comprising correlations and one or more of delay spreads or coherence bandwidth, Channel Quality Information (CQI), Channel Estimation Error (CEE) and User Equipment (UE) Speed Indication Information (SII) of the total channels of different UEs;

selecting a part of the UEs into a group based on their total channel parameters such that it improves system performance when Amplify and Forward Relays (AFRs) are present, wherein the improved performance comprises one or more of Multi-User MIMO (MU-MIMO) beamforming, increased system throughput, reduced computational load, and reduced power consumption;

allocating frequency resources to the group of UEs;

computing precoding and/or detection matrix using total channel matrix of the UEs in the group on the allocated frequency resources; and

performing MU-MIMO beamforming with the UEs in the group on the allocated frequency resources with AFRs present.

36. The method of claim 35, further comprising

dividing the UEs in the group to be served that are in the same time slot into two or more subgroups, each of which is allocated a part of the available frequency resource.

37. A method for Multi-User Multiple-Input-Multiple-Output (MU-MIMO) communication comprising

a MU-Beamformer using a Line-of-Sight (LoS) dependent frequency including a millimeter-wave frequency with highly directive beams to communicate with a plural of selected User Equipment (UEs);

and

closely located selected UEs communicating using a Device to Device short-range wireless link to coordinate the direction of each UE'"'"'s transmitting and/or receiving beam, such that the UEs tune their transmitting and/or receiving antenna beam directions to facilitate MU-MIMO communication with the multiple beams from the MU-Beamformer and/or one or more Amplify and Forward Relays.

38. A Multi-User Multiple-Input-Multiple-Output (MU-MIMO) communication system comprising

one or more millimeter-wave MU-Beamformers (MU-BFers) which use multiple LoS dependent highly directive beams to provide wireless backhauls to multiple small cells simultaneously;

a set of Amplify and Forward Relays (AFRs), working in conjunction with the MU-BFer(s) to overcome the LoS dependence, and/or to increase the multi-path richness of the channel between the MU-BFer(s) and the targeted small cell(s); and

a set of small cells operating in a different frequency than the millimeter-wave wireless backhaul.

39. A method of Multi-User Multiple-Input-Multiple-Output (MU-MIMO) communication comprising

estimating a number of Radio Frequency (RF) paths and/or antennas needed in a MU-MIMO system based on a number of selected User Equipment (UEs), Signal to Interference and Noise Ratio (SINR) needed to support a desired modulation and coding scheme, and estimation of the channels;

and

allocating a sufficient number of RF paths and/or antennas to perform the MU-MIMO communication with the selected UEs.