According to a first aspect a network node device is provided, comprising: a radio transceiver configured to receive a data sequence from a plurality of user equipment over first and second sets of resource elements, wherein the first set is mapped non-orthogonally and the second set is mapped orthogonally. The network node device further comprises a processor configured to determine channel vectors based on at least the data sequence received over the first set of resource elements or the second set of resource elements, and to utilize the data sequence received over the second set of resource elements to associate the determined channel vectors with each of the plurality of user equipment.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

This application provides example signal processing methods, media, and apparatuses. One example method includes obtaining a scattering parameter matrix of passive echoes in an antenna system by a network device. The m virtual user directions are determined by the network device based on the scattering parameter matrix of the passive echoes, where the m virtual user directions are m directions in which total signal strength of the passive echoes is highest, and m is a positive integer. A target beam is formed based on n real user directions and the m virtual user directions, where one or more nulls of the target beam are aligned with the m virtual user directions, n is a positive integer, and n+m?k.

The disclosure relates to an audio processing apparatus for localizing an audio source. The audio processing apparatus comprises a plurality of audio sensors, including a primary audio sensor and at least two secondary audio sensors, configured to detect an audio signal from a target audio source, wherein the primary audio sensor defines at least two pairs of audio sensors with the at least two secondary audio sensors; and processing circuitry configured to: determine for each pair of audio sensors a first set of likelihoods of spatial directions of the target audio source using a first localization scheme; determine a second set of likelihoods of spatial directions of the target audio source using a second localization scheme; and determine a third set of likelihoods of spatial directions of the target audio source on the basis of the first sets of likelihoods and the second set of likelihoods.

A communication device for providing an explicit channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive, from a transmitter a radio signal via a radio time-variant frequency MIMO channel, the radio signal including downlink reference signals according to a reference signal configuration, and downlink signals including the reference signal configuration, and a processor. The processor estimates the CSI using measurements on the downlink reference signals of the radio channel according to the reference signal configuration over one or more time instants/slots, constructs a frequency-domain channel tensor using the CSI estimate, performs a higher-order principal component analysis, HO-PCA, on the channel tensor, identifies a plurality of dominant principal components of the channel tensor, thereby obtaining a compressed channel tensor, and reports to the transmitter the explicit CSI including the dominant principal components of the channel tensor.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Antennas and MIMO antenna arrays in a housing of an electronic device are described. The MIMO antenna array includes a plurality of antennas. At least one of the antennas has operating frequency ranges of 700 MHz-900 MHz, 1700 MHz-2100 MHz, and 3 GHz-5 GHz. The MIMO antenna array may include 8 or 10 antennas.

This invention presents methods for MU-MIMO wireless communication systems comprising a BS with plural of antennas placed as a linear array or planar array, plural of UEs, for conducting two-level signal processing at the BS to reduce the system implementation complexity, i.e., the RF precoding/combination and the baseband precoding/detection, for the BS to obtain the second-order statistical information of the channel matrix of each UE to computing the RF precoding matrix through a much smaller number of pilots than that of the transceiving antennas at the BS, where the second-order statistical information of the channel matrix can be obtained through the uplink reference signals or downlink reference signals plus uplink feedback.

A peak power reduction device includes a unit for dividing digital information to be transmitted into a plurality of streams; a unit for selecting the modulation level of the streams and distribution of transmission power according to a transmission state; a unit for performing singular-value decomposition on the transmission path characteristic of a streams and precoding the resultant data by a right singular value matrix; a unit for performing complex mapping on the subcarrier of a stream according to the modulation level; a unit for converting a complex mapping signal into a time domain signal; a first unit for storing a conversion result as a time domain signal; a second unit for calculating a peak time signal exceeding a predetermined threshold value from a peak value, if any exists, that exceeds a prescribed threshold value for the amplitude of the time domain signal.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.