Patent classifications
H04B7/0854
PHASE NOISE SUPPRESSION METHOD FOR A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) SYSTEM WITH A PLURALITY OF CO-REFERENCE CHANNELS
A phase noise suppression method for a multiple-input multiple-output (MIMO) system with a plurality of co-reference channels includes: dividing the phase noise of each channel in the MIMO system into common phase noise and independent phase noise, and constructing a certain number of joint phase states for the independent phase noise; inserting a pilot sequence into the sent signal based on a preset cycle, obtaining the common phase noise based on the pilot at receiver, and performing compensation; and performing signal demodulation on each joint state of the independent phase noise, and comparing the posterior log likelihood values to select the optimal result to output. The above method can significantly improve the phase noise suppression performance of the MIMO system with a plurality of co-reference channels, thereby providing support for improving the system capacity by using MIMO technology.
METHOD FOR CALIBRATING A MULTI-CHANNEL RADIO RECEIVER
The invention relates to a method for calibrating a receiver comprising a plurality of analog reception channels each including an antenna element of a multi-element antenna, the plurality of analog reception channels comprising a reference channel, the method comprising determining (E1-E4) and correcting (E5), for each analog reception channel other than the reference channel, a phase shift with the reference channel, said determination comprising: calculating (E1) an observed covariance matrix (R.sub.ZZ.sup.t,e) representative of the covariance between samples (Z.sub.t.sup.e), collected in parallel on each of the analog reception channels over a period of time, of one or more incident reference radio signals on the multi-element antenna, obtaining (E2) an estimate () of a reference covariance matrix representative of the covariance between samples of said incident radio signal(s) which would be collected in parallel on each of the analog reception channels over the period of time in the absence of phase shift between the analog reception channels, calculating (E3) a product matrix (
), resulting from the term-by-term matrix product of the observed covariance matrix with the estimate of the reference covariance matrix; determining (E4) the argument (
) of complex terms of the product matrix.
TECHNIQUES FOR ENABLING BEAM MANAGEMENT RADIO RESOURCE CONTROL PARAMETERS
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a radio resource control (RRC) message, the RRC message including an indication of whether group-based beam reporting is enabled for the UE. The UE may transmit a group-based beam report based at least in part on the indication that the group-based beam reporting is enabled for the UE. Numerous other aspects are described.
Beam alignment for electronically steered antennae systems
A method of auto-aligning a beam within a receiving electronically steered antenna system comprising a plurality of antenna elements is provided. The method comprises the steps of: providing a list of codes, wherein each code is embedded in signals transmitted by a respective transmitting entity, and identifies the transmitted signal as originating from said transmitting entity; selecting a transmitter and identifying a corresponding code for that transmitter; and for each antenna element: receiving a first communications signal; receiving a second signal representative of first communications signals received by each of the plurality of antenna elements; correlating the first and second signals with the identified code to generate first and second output signals; comparing the first and second output signals and determining a phase shift and/or time delay for minimizing the difference between the first and second output signals; and applying the phase shift and/or time delay to the first received communication signal.
RECEPTION-SIDE APPARATUS AND RADIO COMMUNICATION METHOD
A reception-side apparatus includes: M receive antennas; and a processor configured to execute a first process of acquiring a first signal received from a first transmission-side apparatus from among signals simultaneously received from the N transmission-side apparatuses by receive diversity processing, and acquiring first data by demodulating and decoding the first signal. In the case of N>M, the processor acquires, for each of all patterns of a combination of a first signal, second signals from M−1 transmission-side apparatuses which are to be cancelled by receive diversity processing and third signals from N−M transmission-side apparatuses which are not to be cancelled by the receive diversity processing, a power ratio of power of the first signal relative to total power of the second and third signals based on a predetermined weight and a channel estimate of each signal, and selects a combination with the largest power ratio from among all the patterns.
TECHNIQUE FOR POST-CORRELATION BEAMFORMING
A receiver system for correlating one or more signals (beam patterns) is disclosed. One or more antenna elements are configured to receive the signals. A controller generates correlator outputs based on a first set of duplicated signals, generates a first set of beams based on the one or more correlator outputs using a first beamforming module, generates a second set of beams based on a second set of duplicated signals using a second beamforming module, generates one or more power estimates based on the second set of beams, and divides each of the first set of beams by a corresponding power estimate to generate one or more normalized correlations.
Systems and methods for multiuser detection in distributed antenna systems
The present embodiments relate to multi user detection in distributed antenna systems. A communication system may include a central processing circuitry and a plurality of access points connected to the central processing circuitry via a fronthaul interface. Each access point of the plurality of access points may include a plurality of antennas configured to receive signals from a plurality of UEs, and a local processing circuitry connected to the plurality of antennas. The local processing circuitry may be configured to estimate channel properties of a MIMO channel between the UEs and the antennas of the access point, and determine a subset of the UEs using the channel properties. The local processing circuitry may transmit data associated with the subset of wireless communication devices to the central processing circuitry for use to perform multiuser detection at the central processing circuitry.
NULLING FOR INTER-USER EQUIPMENT INTERFERENCE CANCELLATION
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first mobile station may determine at least one of a channel between the first mobile station and a second mobile station or a relative direction between the first mobile station and the second mobile station. The first mobile station may apply nulling to a communication between the first mobile station and a base station based at least in part on the at least one of the channel between the first mobile station and the second mobile station or the relative direction between the first mobile station and the second mobile station. Numerous other aspects are described.
UPLINK RECEIVE BEAMFORMING FOR HIGH MOBILITY USER IN NETWORKS WITH CLOUD RADIO ACCESS NETWORK (C-RAN) ARCHITECTURE
Various embodiments herein provide techniques for minimum mean-square error interference rejection combining (MMSE-IRC) processing of a received signal, distributed between a baseband unit (BBU) and a remote radio unit (RRU). The RRU may perform uplink receive beamforming (e.g., using maximum ratio combining (MRC)) based on multiple channel measurements (e.g., a set of multiple sounding reference signal (SRS) channel measurements) obtained on respective measurement signals transmitted by a user equipment (UE). The RRU may send the processed signal to the BBU for further processing. The BBU may perform MMSE-IRC based on the processed signal received from the RRU, e.g., using demodulation reference signals (DM-RSs). Other embodiments may be described and claimed.
COMMUNICATIONS USING DYNAMIC BEAM WEIGHTS
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine, based at least in part on at least one of a plurality of conditions being met, to switch from a static analog beamforming codebook to a dynamic analog beamforming beam weight calculation for selecting beam weights for communications between the UE and a base station. The UE may select the beam weights for the communications using the dynamic beam weight calculation. The UE may communicate, using the beam weights, with the base station. Numerous other aspects are described.