Control channel design for many-antenna MU-MIMO systems
AssigneeSkylark WL Holdings, LLC
InventorsClayton W. Shepard, Lin Zhong, Abeer Javed, Hang Yu
Life of this patent
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Abstract
Disclosed embodiments include methods for control channel design in many-antenna multi-user (MU) multiple-input multiple-output (MIMO) wireless systems. A beacon comprising an identifier of a many-antenna base station is encoded into a base sequence. A plurality of synchronization sequences is generated based on the encoded base sequence and a set of orthogonal beam sequences. The many-antenna base-station transmits, using a plurality of antennas, the plurality of synchronization sequences in a plurality of beam directions associated with the set of orthogonal beam sequences for synchronization and associated with users without knowledge of channel state information (CSI).
Claims16
A method for optimizing wireless communications by a base station (BS), wherein said method exhibits 2 modes of operation, a no-CSI (open-loop) mode and a CSI (MIMO) mode, said no-CSI (open-loop) mode occurring before said BS has CSI knowledge of supported active users and said CSI (MIMO) mode occurring after time-frequency synchronization and collection of channel state information (CSI), comprising:
- generating a plurality of synchronization sequences;
- transmitting a single synchronization sequence, from said plurality of sequences, optionally followed by at least one repetition of said synchronization sequence at the beginning of a frame transmission;
- encoding a geographically locally unique identifier (ID) of said many-antenna BS into each of said plurality of transmitted synchronization sequences;
- generating a set of beamforming weights allowing for spatial directional transmission of beam patterns within specific regions;
- altering beam patterns by changing beam forming weights, applied to each antenna of said many-antenna BS, to modify the amplitude and phase of the signal sent from said many-antenna BS antenna;
- transmitting, using a plurality of BS antenna, synchronization sequences sent in a plurality of beam directions associated with said beamforming weights;
- receiving, by user equipment (UE), said geographically locally unique ID of said many-antenna BS via said synchronization sequences;
- simultaneously identifying and synchronizing with said many-antenna BS through synchronization sequence decoding;
- transmitting an uplink pilot from the UE;
- estimating, by said many-antenna BS, channel state information (CSI) associated with the UE based on the received uplink pilot from the UE to the many-antenna BS;
- collecting UE CSI from said uplink pilot;
- establishing a CSI mode (MIMO communication) link between said many-antenna BS and said UE based on collected CSI;
- using collected CSI between said many-antenna BS and UE to calculate beamweights that maximize signal strength at the UE and minimize destructive interference at the UE;
- receiving, at said many-antenna BS location, CSI and/or said uplink pilots of the UE;
- and
- steering beams of data toward said UE based on the received location information and/or said uplink pilots.
Dependencies are inferred from the claim text.