Precoding matrix computations for a large number of antenna arrays can be used to generate efficiencies within a wireless network. Utilizing network topology and context data in conjunction with known available network resources and mobile device measurements can facilitate gains in power and spectral efficiency and reduction in computation complexity posed by current procedures. To take advantage of multiple paths, the precoding matrix can be known at the radio units for each mobile device.

A method, system, and computer program are described for identifying the presence of narrowband signals within a wide instantaneous bandwidth by exploiting the spatial diversity of the received signals using an array aperture to provide detection capability. For example, the method includes receiving and channelizing digitized signals into signals with a narrow bandwidth of interest. The method further includes estimating covariance matrices associated with the signals, determining a set of Eigenvalues for the covariance matrices, and analyzing each Eigenvalue to determine a rank change estimate. The method further includes identifying one or more of the signals that have a positive rank change estimate, computing a beam forming weight and direction estimate for each signal that has a positive rank change estimate, and outputting an indication of the signals that have a positive rank change estimate including one or more of fine timing information, the beamforming weights, and the direction estimate.

A method, system, and computer program are described for identifying the presence of narrowband signals within a wide instantaneous bandwidth by exploiting the spatial diversity of the received signals using an array aperture to provide detection capability. For example, the method includes receiving and channelizing digitized signals into signals with a narrow bandwidth of interest. The method further includes estimating covariance matrices associated with the signals, determining a set of Eigenvalues for the covariance matrices, and analyzing each Eigenvalue to determine a rank change estimate. The method further includes identifying one or more of the signals that have a positive rank change estimate, computing a beam forming weight and direction estimate for each signal that has a positive rank change estimate, and outputting an indication of the signals that have a positive rank change estimate including one or more of fine timing information, the beamforming weights, and the direction estimate.

A network node device includes a radio transceiver configured to receive a data sequence from a plurality of user equipments (UEs) over first and second sets of resource elements, wherein the first set of resource elements 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 at least in part on the data sequence received over the first set of resource elements or over the second set of resource elements, and to utilize the data sequence as received over the second set of resource elements to associate the determined channel vectors with each of the plurality of UEs.

User terminal 20 configured to perform MIMO transmission with radio base station 10 includes: control section 200 configured to generate first channel estimation information based on a reference signal transmitted by radio base station 10, and perform an operation for elimination of an interference signal on the first channel estimation information to generate second channel estimation information; and postcoder 208 configured to perform postcoding, based on the second channel estimation information, on a data signal to be transmitted by the radio base station 10, so as to detect a desired signal.

Precoding matrix computations for a large number of antenna arrays can be used to generate efficiencies within a wireless network. Utilizing network topology and context data in conjunction with known available network resources and mobile device measurements can facilitate gains in power and spectral efficiency and reduction in computation complexity posed by current procedures. To take advantage of multiple paths, the precoding matrix can be known at the radio units for each mobile device.

Mechanisms for recovering data symbols in multiple-input, multiple-output (MIMO) receivers, the mechanisms comprising receiving, at N.sub.a antennas that each have an output: first signals corresponding to N.sub.p pilot symbols transmitted from each of K transmitters for a total of N.sub.p*K transmitted pilot symbols; and second signals corresponding to a plurality of transmitted data symbols transmitted from the K transmitters, wherein N.sub.p is less than N.sub.a, and wherein K is less than N.sub.a; receiving, at a hardware processor, first digital signals representing the N.sub.p*K transmitted pilot symbols; receiving, at the hardware processor, second digital signals representing the plurality of transmitted data symbols; and recovering the plurality of transmitted data symbols using the second digital signals and no more pilot symbols than the N.sub.p*K transmitted pilot symbols represented by the first digital signals using the hardware processor.

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.

A method of transmission over multiple wireless channels in a multiple antenna system includes storing channel modulation matrices at a transmitter; receiving quantized channel state information at the transmitter from plural receivers; selecting a transmission modulation matrix using the quantized channel state information from the stored channel modulation matrices; and transmitting over the multiple channels to the plural receivers using the selected transmission modulation matrix. In another embodiment, the method includes storing, at one or more receivers, indexes of modulation matrices generated by a capacity enhancing algorithm; upon a selected one of the one or more receivers receiving a transmission from the transmitter, the selected receiver selecting a modulation matrix from the stored modulation matrices that optimizes transmission between the transmitter and the selected receiver; the selected receiver sending an index representing the selected modulation matrix; and receiving the index at the transmitter from the selected receiver.

A system includes first and second sets of communication devices. A processor coupled to the first set of communication devices produces a first encoded vector and transmits the first encoded vector to the second set of communication devices via a communication channel that applies a channel transformation to the first encoded vector during transmission. A processor coupled to the second set of communication devices receives the transformed signal, detects an effective channel thereof, and identifies left and right singular vectors of the effective channel. A precoding matrix is selected from a codebook of unitary matrices based on a message, and a second encoded vector is produced based on a second known vector, the precoding matrix, a complex conjugate of the left singular vectors, and the right singular vectors. The second encoded vector is sent to the first set of communication devices for identification of the message.