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.

A transmission method using a massive MIMO (Multiple-Input and Multiple-Output) scheme with an arrangement 108 of N.sub.mN.sub.b antenna elements at the transmitter, arranged in N.sub.m sets of N.sub.b antenna elements or N.sub.b sets of N.sub.m antenna elements based on SC-FDE (Single-Carrier with Frequency Domain Equalization) schemes with large constellations that is compatible with low-cost, highly-efficient, nonlinear amplifiers 106, while allowing spatial multiplexing gains. The transmission structure of this transmission method decomposes in 103 the modulated symbols from 102 associated to a given constellation as the sum of N.sub.m polar components that are modulated as N.sub.m BPSK (Binary Phase Shift Keying) signals. Each of these BPSK signals can be regarded as an OQPSK (Offset Quadrature Phase Shift Keying) signal in the serial format that is specially designed to have good tradeoffs between reduced envelope fluctuations and a compact spectrum.

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.

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.

A device may include an antenna subsystem to support image sensing and wireless network communications. A device may include a localization subsystem to determine a location of a wireless base station within a defined region via computational imaging of the region using an image-sensing antenna of the antenna subsystem operating at a sensing frequency within the operational frequency band of the wireless base station. A device may include a communication subsystem to adjust a steering angle of a communication antenna based on the location of the wireless base station as determined by the localization subsystem.

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.

Multi-mode multi-input multi-output (MIMO) radar sensors are described herein. An example MIMO radar sensor includes a receiver module including an array of receiver antenna elements to receive radar signals and a transmitter module including an array of transmitter antenna elements. Groups of the transmitter antenna elements form transmitter chains. The example MIMO radar sensor further includes a control system to, in a first mode, activate a first set of the transmitter antenna elements of each of the transmitter chains, and, in a second mode, activate a second set of the transmitter antenna elements of each of the transmitter chains, where the second set is larger than the first set. The transmitter antenna elements are arranged such that distances between phase centers of the transmitter chains in the first mode and the second mode are the same.

Systems and methods are described for coordinating transmissions in distributed wireless systems via user clustering. For example, a method according to one embodiment of the invention comprises: measuring link quality between a target user and a plurality of distributed-input distributed-output (DIDO) distributed antennas of base transceiver stations (BTSs); using the link quality measurements to define a user cluster; measuring channel state information (CSI) between each user and each DIDO antenna within a defined user cluster; and precoding data transmissions between each DIDO antenna and each user within the user cluster based on the measured CSI.

A system and method are described which enable planned evolution and obsolescence of multiuser wireless spectrum. One embodiment of such a system includes one or multiple centralized processors and one or multiple distributed nodes that communicate via wireline or wireless connections. The distributed nodes may share their identification number and other reconfigurable system parameters with the centralized processor. The information about all distributed nodes may be stored in a database that is shared by all centralized processors. The reconfigurable system parameters may comprise power emission, frequency band, modulation/coding scheme. The distributed nodes may be software defined radios such as FPGA, DSP, GPU and/or GPCPU that run algorithms for baseband signal processing and may be reconfigured remotely by the centralized processor. A cloud wireless system may be used wherein the distributed nodes are reconfigured periodically or instantly to adjust to the evolving wireless architecture.

A NodeB for a WCDMA system, arranged to transmit instructions to a UE for the UE's uplink transmissions. The NodeB is arranged to transmit the instructions on a dedicated downlink physical channel which the NodeB is arranged to use for transmissions to a plurality of UEs and which comprises a plurality of radio frames, where each radio frame comprises a number of slots and each slot comprises a number of WCDMA symbols. The instructions to the UE comprise Transmit Power Commands as well as other instructions to the UE for the UE's uplink transmissions. The NodeB is arranged to use a first WCDMA slot format for the TPC commands to the UE and a second WCDMA slot format for the other instructions to the UE.