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US 11,452,173 B2Granted
Remote radio head, beamforming method and storage medium
AssigneeNEC Corporation
InventorsDileep Kumar, Kazushi Muraoka, Naoto Ishii
Life of this patent
Estimating the term…
Abstract
Provided a Remote Radio Head (RRH) with multiple antennas generating a plurality of analog beams in a wireless communication system serving at least one user terminal, including a metric calculator that calculates at least one metric representing a traffic demand as a function of spatial direction by using at least a signal of each Radio Frequency chain and a beam former that generates analog beams directed towards a spatial direction determined based on the calculated at least one metric.
Claims17
A remote radio head comprising:
- a plurality of sub-arrays, each having a plurality of antenna elements;
- a plurality of Radio Frequency chains, each performing transformation from a digital baseband signal received via a digital interface from a baseband unit to an RF (radio frequency) signal and from an RF signal received to a digital baseband signal that is to be sent via the digital interface to the baseband unit;
- a plurality of RF front ends, each performing at least one of transmission of RF signals to the antenna elements of the corresponding sub-array and synthesis of RF signals received from the antenna elements of the corresponding sub-array;
- a plurality of sets of phase shifters, each set connected between the corresponding RF front end and the antenna elements of the corresponding sub-array;
- the digital interface that performs at least one of transmission and reception of a digital signal to and from the plurality of the Radio Frequency chains;
- a memory storing program instruction;
- and
- a processor connected to the memory and configured to:
- monitor a power level of at least a signal inputted to or outputted from each of the Radio Frequency chains;
- calculate at least one metric representing a traffic demand as a function of spatial direction, by using at least the power level of the at least the signal inputted to or outputted from the each of the Radio Frequency chains;
- determine a spatial direction, based on the at least one metric currently calculated and metrics calculated previously;
- and
- control each set of phase shifters corresponding to the each of the Radio Frequency chains to direct analog beams towards the spatial direction.
10 more elements
A beamforming method performed in a remote radio head including:
- a plurality of sub-arrays, each having a plurality of antenna elements;
- a plurality of Radio Frequency chains, each performing transformation from a digital baseband signal received via a digital interface from a baseband unit to an RF (radio frequency) signal and from an RF signal received to a digital baseband signal that is to be sent via the digital interface to the baseband unit;
- a plurality of RF front ends, each performing at least one of transmission of RF signals to the antenna elements of the corresponding sub-array and synthesis of RF signals received from the antenna elements of the corresponding sub-array;
- a plurality of sets of phase shifters, each set connected between the corresponding RF front end and the antenna elements of the corresponding sub-array;
- and
- the digital interface that performs at least one of transmission and reception of a digital signal to and from the plurality of the Radio Frequency chains,
- the method comprising:
- monitoring a power level of at least a signal inputted to or outputted from each of the Radio Frequency chains;
- and
- calculating at least one metric representing a traffic demand as a function of spatial direction, by using at least the power level of the at least the signal inputted to or outputted from the each of the Radio Frequency chains;
- determining a spatial direction, based on the at least one metric currently calculated and metrics calculated previously;
- and
- controlling each set of phase shifters corresponding to the each of the Radio Frequency chains to direct analog beams towards the spatial direction.
10 more elements
A non-transitory computer-readable storage medium storing a program executed by a computer embedded on a remote radio head including:
- a plurality of sub-arrays, each having a plurality of antenna elements;
- a plurality of Radio Frequency chains, each performing transformation from a digital baseband signal received via a digital interface from a baseband unit to an RF (radio frequency) signal and from an RF signal received to a digital baseband signal that is to be sent via the digital interface to the baseband unit;
- a plurality of RF front ends, each performing at least one of transmission of RF signals to the antenna elements of the corresponding sub-array and synthesis of RF signals received from the antenna elements of the corresponding sub-array;
- a plurality of sets of phase shifters, each set connected between the corresponding RF front end and the antenna elements of the corresponding sub-array;
- and
- the digital interface that performs at least one of transmission and reception of a digital signal to and from the plurality of the Radio Frequency chains,
- the program causing the computer to execute:
- monitoring a power level of at least a signal inputted to or outputted from each of the Radio Frequency chains;
- and
- calculating at least one metric representing a traffic demand as a function of spatial direction, by using at least the power level of the at least the signal inputted to or outputted from the each of the Radio Frequency chains;
- and
- determining a spatial direction, based on the at least one metric currently calculated and metrics calculated previously;
- and
- controlling each set of phase shifters corresponding to the each of the Radio Frequency chains to direct analog beams towards the spatial direction.
11 more elements
Dependencies are inferred from the claim text.