Patent classifications
H04B7/0465
TERMINAL AND RADIO COMMUNICATION METHOD
A terminal according to an aspect of the present disclosure includes: a transmission section that transmits mode 2 capability information indicating that mode 2 of full power transmission is supported; and a control section that, in a case where the mode 2 capability information is transmitted and transmitted precoding matrix indicator (TPMI) group capability information regarding a TPMI group is not transmitted, assumes that a number of SRS ports=1 is configured for at least one SRS resource included in a measurement reference signal (sounding reference signal (SRS)) resource set of which usage is a codebook. According to one aspect of the present disclosure, it is possible to control full power transmission appropriately.
WIRELESS COMMUNICATION METHODS AND APPARATUS
In an embodiment, a wireless communication method of transmitting a plurality of data streams from a transmitter to a receiver is disclosed. The transmitter comprises a plurality of antennas. The method comprises: encoding each of the data streams as a sequence of code words; determining a plurality of precoding transmit coefficients from channel information for each of a plurality of subcarriers, the precoding transmit coefficients defining spatial channels between the plurality of antennas of the transmitter and the receiver; determining a set of power loading factors for each spatial channel between the receiver and the transmitter, each set of power loading factors comprising a power loading factor for each of the plurality of subcarriers, by allocating power between the plurality of subcarriers to satisfy a signal to interference and noise target per code word; determining a signal for transmission by each antenna of the plurality of antennas by applying respective precoding coefficients and power loading factors to each respective sequence of code words; and transmitting each of the sequences of code words on a plurality of subcarriers of at least one of the spatial channels by transmitting the respective signals for transmission from each respective antenna.
Power adjustment to align transmit chain power ratios
Various aspects of the present disclosure generally relate to wireless communication. A wireless communication device may have an apparatus that aligns the non-linearity between transmit chains of the wireless communication device that are driven by the same digital port. The apparatus may adjust an amplification power out or an amplification saturated power to adjust a ratio between the amplification saturated power and the amplification power out for one or more transmit chains of the wireless communication device. The apparatus may adjust the ratios of transmit chains to align the ratios of the transmit chains for more consistent management of non-linear characteristics of the chain components. Numerous other aspects are described.
Millimeter wave-based multi-user massive MIMO-based hybrid beamforming system and analog precoder matrix acquisition method applied thereto
The present inventive concept relates to a method for designing an optimal analog precoder for improving frequency spectrum efficiency in a millimeter wave-based multi-user massive MIMO-based hybrid beamforming system and a hybrid beamforming system applying the same, and more specifically, to a method for designing an optimal analog precoder using an approximation technique and an iterative optimization algorithm, and a hybrid beamforming system to which the same is applied.
Precoder structure for MIMO precoding
The teachings herein present a method and apparatus that implement and use a factorized precoder structure that is advantageous in terms of performance and efficiency. In particular, the teachings presented herein disclose an underlying precoder structure that allows for certain codebook reuse across different transmission scenarios, including for transmission from a single Uniform Linear Array (ULA) of transmit antennas and transmission from cross-polarized subgroups of such antennas. According to this structure, an overall precoder is constructed from a conversion precoder and a tuning precoder. The conversion precoder includes antenna-subgroup precoders of size N.sub.T/2, where N.sub.T represents the number of overall antenna ports considered. Correspondingly, the tuning precoder controls the offset of beam phases between the antenna-subgroup precoders, allowing the conversion precoder to be used with cross-polarized arrays of N.sub.T/2 antenna elements and with co-polarized arrays of N.sub.T antenna elements.
MIMO Antennas
Antenna arrays to be used in MIMO apparatuses are disclosed. Such an antenna array may include a plurality of array elements, wherein every second element in a first direction is a digital pre-distortion-less linear element, and every second element in the first direction is a non-linear element. In the antenna array, spacing between adjacent elements in the first direction is less than a half of a free space wavelength. A non-linear precoding is applied to transmissions from the antenna array, the non-linear precoding converting out-of-band emissions of the transmissions into reactive power in the near-field around the antenna array while ensuring that in-band signals generated by the elements remain unaffected.
Pre-coding method and pre-coding device
Disclosed is a precoding method comprising the steps of: generating a first coded block and a second coded block with use of a predetermined error correction block coding scheme; generating a first precoded signal z1 and a second precoded signal z2 by performing a precoding process, which corresponds to a matrix selected from among the N matrices F[i], on a first baseband signal s1 generated from the first coded block and a second baseband signal s2 generated from the second coded block, respectively; the first precoded signal z1 and the second precoded signal z2 satisfying (z1, z2).sup.T=F[i] (s1, s2).sup.T; and changing both of or one of a power of the first precoded signal z1 and a power of the second precoded signal z2, such that an average power of the first precoded signal z1 is less than an average power of the second precoded signal z2.
Transmission modes and signaling for uplink MIMO support or single TB dual-layer transmission in LTE uplink
An apparatus for mapping data in a wireless communication system. The apparatus includes circuitry for generating a precoding matrix for multi-antenna transmission based on a precoding matrix indicator (PMI) feedback from at least one remote receiver where the PMI indicates a choice of precoding matrix derived from a matrix multiplication of two matrices from a first code book and a second codebook. The apparatus further includes circuitry for precoding one or more layers of a data stream with the precoding matrix and transmitting the precoded layers of data stream to the remote receiver.
Dynamic MU-MIMO Layer Limit Control
To perform wireless communication scheduling, a network node (700) calculates a corresponding layer limit for each of a plurality of scheduling intervals of a cell (20) served to a plurality of user equipment via multi-user multiple-input multiple-output (MU-MIMO). The network node (700) schedules time-frequency resource utilization such that, for each of the scheduling intervals, no time-frequency resource is scheduled for use by more of the UEs (200) than the layer limit corresponding to the scheduling interval.
Device and method for measuring a channel state
[Object] To make it possible to select a cell that is more preferable for a terminal device in an environment in which beamforming is performed. [Solution] There is provided a device including: an acquiring unit configured to acquire received quality information indicating received quality of a reference signal in a terminal device; and a control unit configured to perform cell selection for the terminal device based on the received quality information. When a predetermined condition related to use of weight sets for beamforming by a base station is satisfied, the control unit does not perform the selection based on the received quality information.