360 results about "Mimo communication" patented technology

Optical fiber-based distributed antenna systems that support multiple-input, multiple-output (MIMO) antenna configurations and communications. Embodiments disclosed herein include optical fiber-based distributed antenna system that can be flexibly configured to support or not support MIMO communications configurations. In one embodiment, first and second MIMO communication paths are shared on the same optical fiber using frequency conversion to avoid interference issues, wherein the second communication path is provide to a remote extension unit to remote antenna unit. In another embodiment, the optical fiber-based distributed antenna systems may be configured to allow to provide MIMO communication configurations with existing components. Existing capacity of system components are employed to create second communication paths for MIMO configurations, thereby reducing overall capacity, but allowing avoidance of frequency conversion components and remote extension units.

A method of deploying a distributed antenna system (DAS) is provided. The method comprises outputting first and second signals from a multiple-input and multiple-output base station (MIMO BTS) and coupling a master unit to the MIMO BTS. The method further comprises coupling first and second remote units to the master unit, the first remote unit communicating the first signal over a first air interface located within the environment at a first location, the second remote unit communicating the second signal over a second air interface within the environment at a second location. The first and second remote units are arranged at the first and second locations within the environment and configured to provide signal coverage of both the first signal and the second signal at a third location in the environment to provide the capacity for MIMO communications through the system at the third location.

Systems and methods for receiving MIMO signals for testing and analyzing operation of MIMO communications devices. Examples of systems and / or methods for receiving MIMO signals include a measuring receiver with N RF paths consisting of N downconverters. Each downconverter achieves a frequency shift of the input MIMO signal equal to a shifting frequency of a first intermediate frequency (IF) plus a delta determined by the signal bandwidth multiplied by an integer number between 1 and N. The shifted N MIMO signals are combined to generate one combined analog MIMO signal. An analog to digital converter converts the combined analog MIMO signal to a stream of digital samples where the samples may be tested and analyzed with metrics on signals communicated in a MIMO environment. Example systems and method for receiving MIMO signals may also be implemented as a MIMO channel emulator such that samples generated by the ADC may be upconverted to output copies of the original signals to a receiver DUT, for example.

Using at least one MIMO-capable transceiver allows weighting calculations for signals transmitted and received, and enables individual packets to adapt, in a scalable, flexible, and responsive fashion to the real-world dynamics of a continuously varying communications network environment. The method and system of this invention use adaptively-derived diversity means to rapidly and efficiently distinguish the desired signal from noise, network interference, and external interference impinging on the network's transceivers and can transmit with lessened overhead. ADC operations and signal transformations continuously update combiner weights to match dynamically-varying environmental and traffic conditions, thereby continuously matching necessitated signal and waveform transformations with environmental and signal effects and sources. Successive iterations of the adaptation algorithm let each node's multiport combiner and distribution weights approach the MIMO channel's Shannon capacity in high-rate networks, or to minimize power needed to close links at a specified rate in low-rate networks, e.g. Voice-Over-IP networks.

The present invention describes a method of closed loop MIMO communication utilizing implicit or explicit channel state information (CSI) at the transmitter and the receiver. The transmitter performs linear pre-processing (for example, QR decomposition or bi-diagonal decomposition or Jacobi rotations, and / or sporadic SVDs) on a channel matrix, and the receiver mitigates the mutual interference between the streams by performing MMSE processing on the received signals. The MMSE matrix is computed with respect to the processed channel that may estimated by the receiver through preprocessed pilot signals. The transmitters preprocessing is of much lesser cost and complexity than full SVD.

A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a first preamble for a first antenna of the MIMO communication, wherein the first preamble includes a carrier detect field, a first channel select field, a first signal field, and a second signal field. The method continues by generating a second preamble for at least one other antenna of the MIMO communication, wherein the second preamble includes the carrier detect field, a plurality of channel select fields, and the second signal field. The method continues by simultaneously transmitting the carrier detect field via the first antenna and the least one other antenna. The method continues by transmitting the first channel select field and the first signal field via the first antenna. The method continues by, subsequent to the transmitting the first channel select field and the first signal field via the first antenna, transmitting the plurality of channel select fields via the at least one other antenna. The method continues by simultaneously transmitting the second signal field via the first antenna and the at least one other antenna.

A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a first preamble for a first antenna of the MIMO communication, wherein the first preamble includes a carrier detect field, a first channel select field, a first signal field, and a second signal field. The method continues by generating a second preamble for at least one other antenna of the MIMO communication, wherein the second preamble includes the carrier detect field, a plurality of channel select fields, and the second signal field. The method continues by simultaneously transmitting the carrier detect field via the first antenna and the least one other antenna. The method continues by transmitting the first channel select field and the first signal field via the first antenna. The method continues by, subsequent to the transmitting the first channel select field and the first signal field via the first antenna, transmitting the plurality of channel select fields via the at least one other antenna. The method continues by simultaneously transmitting the second signal field via the first antenna and the at least one other antenna.

In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter (250) and a receiver (260) each using a cross-polarized antenna structure, a channel estimating and precoding selection section (214) of the receiver (260) performs a channel estimation of MIMO channels from the transmitter to the receiver, decides a precoding matrix (P) of a projection matrix for mutually orthogonalizing or substantially orthogonalizing the channel response matrixes for respective different polarized waves, and feeds the determined precoding matrix (P) back to the transmitter (250). In the transmitter (250), a precoding processing section (208) applies the precoding matrix (P) to the spatial stream corresponding to one of the polarized waves to perform a precoding, thereby allowing the transmitter (250) to transmit the polarized waves with the orthogonality therebetween maintained.

A solution for optimizing beamforming configurations and transmit power allocation configurations in a telecommunication system comprising a base station and a plurality of user entities is provided. The base station and the user entities are capable of multiple-input multiple-output (MIMO) communications, i.e. capable of communicating through spatial subchannels. The base station calculates iteratively optimal beamforming configurations for the base station and for each user entity and transmit power allocation configurations for each spatial subchannel used in MIMO communications. The base station carries out the calculation on the basis of channel state information received from the user entities by utilizing the information on correlation of different spatial subchannels, i.e. interference between the subchannels, in order to update beamforming configurations and transmit power allocation configurations.

A multi-input-multi-output (MIMO) communications system is provided for conveying signals over a MIMO channel. The system includes a precoder for precoding a signal based upon a uniform channel decomposition scheme. The system further comprises a transmitter in communication with the precoder for conveying the precoded signal over a subchannel of the MIMO channel.

The disclosed invention implements SVD-MIMO communication efficiently with a less number of high-load calculation required for singular value decomposition (SVD) processing for a channel matrix. A receiver derives a channel matrix H from a reference signal from a transmitter and acquires downlink transmit weights V and receive weights UH by SVD of the channel matrix H. The receiver transmits a reference signal weighted with U* to the transmitter, where U* is a conjugate matrix for U as uplink transmit weights. The transmitter receives the reference signal weighted with U* and separates the signal into downlink transmit weights V and a diagonal matrix D, based on unitary matrix properties.

A method and apparatus for communication in millimeter wave multiple input multiple output (MIMO) communication are provided. A beamforming matrix by groups for terminals that are classified into a group is generated, and a pilot signal that is beam-formed based on the generated beamforming matrix by groups is transmitted to the terminals. Channel information based on the pilot signal is received from the terminals, hybrid beamforming scheduling is performed based on the channel information, and data is transmitted to the terminals based on the scheduling.

Methods and systems for carrying different signals required for MIMO communication using a single coaxial cable between two endpoints of a distributed antenna system (DAS) network. Original MIMO signals having the same frequency are frequency-separated at a first endpoint of the network. The frequency-separated signals are propagated together over the single coaxial cable and then reconstructed to their original frequency at a second endpoint of the network.

In order to transmit a large amount of data in series at a time with a MIMO communication scheme while avoiding deterioration of decoding characteristics due to change over time by a channel matrix, a wireless communication system uses an open-loop type and a closed-loop type of MIMO communication modes in combination and switches to the open-loop MIMO communication mode in response to the information that the amount of data to be transmitted at a time has exceeded a predetermined amount of bits or a predetermined transmission time during data transmission under the closed-loop MIMO communication mode. By discontinuing useless closed-loop MIMO communication and switching to the open-loop MIMO communication mode that is better than Zero-forcing, the decoding characteristics are prevented from simply becoming deteriorated.

The present invention relates to a wireless communication system (C) comprising at least one base station (1) in a communication cell (2), from which base station (1) at least two essentially uncorrelated antenna radiation lobes (7, 8, 9, 10) are formed. Each antenna radiation lobe (7, 8, 9, 10) communicates a MIMO (Multiple Input Multiple Output) communication stream. The system (C) further comprises at least one repeating transmitter / receiver (repeater) (18, 19, 20, 21), which is arranged for communicating one of the MIMO communication streams to and / or from at least one UE (user equipment) (12). The present invention also relates to a repeater that is a part of the system (C), and a method for communicating at least two MIMO communication streams to and / or from at least one UE (user equipment) (12), using at least one repeater (18, 19, 20, 21).

The invention relates to a wireless outdoor-indoor multiple-input multiple-output (MIMO) communications system for communicating with user equipment located inside a physical structure such as a building. The MIMO communication system is comprised of a node having at least two node antennas, wherein the node is configured for line of sight (LOS) wireless MIMO communication with at least two outdoor-indoor repeaters, and of at least two outdoor-indoor repeaters adapted for LOS wireless MIMO communication with the node. The repeaters have at least one repeater antenna each, provided outside the physical structure, for LOS MIMO communication with the node and at least two DASs each, provided inside the physical structure, for indoor MIMO communication with the user equipment located inside the physical structure. The repeaters are provided outside on the same physical structure and spaced well-apart, and each DAS of each repeater is provided such that they provide the same indoor coverage of the same interior space in the physical structure.

A method, MIMO communication device and electronic storage medium for mapping symbols during a duration of each plural consecutive frames of each of a plurality of first data streams (10, 12, 14, 16, 18, 20, 22, 24, 26) to frames of a plurality of second data streams (spaced-time coded streams or antenna streams); and varying the mapping during the duration of each of the plural consecutive frames of each of the plurality of first data streams (10, 12, 14, 16, 18, 20, 22, 24, 26).

The disclosed invention enhances transmission efficiency by decreasing regions of reference signals which are attached to transmit packets from a transmitter during bidirectional SVD-MIMO communication. The transmitter transmits user data following a reference signal. At the other end, the receiver acquires a channel matrix, based on the reference signal attached preceding the user data, receives the user data, while weighting the data with receive weights derived from the channel matrix, adaptively estimates the channel matrix H as long as the user data is being received, and obtains transmit weights V′ for transmitting user data in the reverse direction from an adaptively estimated channel matrix H′.

The invention discloses a signaling field of a wireless MIMO communication system. The signaling field comprises a scrambling code initializing subfield for allocating the scrambling code state, a single carrier / orthogonal frequency-division multiplexing subfield for finishing single carrier and orthogonal frequency-division multiplexing transmission, a dynamic bandwidth allocation subfield, a spatial flow allocation subfield and a length subfield for allocating the length of sent data. The invention further provides a frame structure based on the signaling field and a wireless MIMO communication method with the frame structure adopted. The dynamic bandwidth is achieved more easily, and the spectral efficiency is effectively improved. By means of the signaling field and the communication method of the wireless MIMO communication system, multi-user and multi-flow allocation and allocation of a plurality of carrier sending modes are achieved more effectively.

The present invention relates to a control method for a communication network that has a transmitter with an array of transmit antennas and that has at least one receiver communicating with the transmitter. The receiver performs a channel measurement for a receive antenna of the receiver using a signal transmitted from the transmitter to the receiver. The receiver further determines channel coefficients for each of an array of transmit antennas at the transmitter from an output of the channel measurement, and then applies a linear, reversible and orthogonal transform to the channel coefficients, thus ascertaining channel component coefficients indicative of the individual weight of respective channel components in a transform domain. The receiver then selects one or more channel components in the transform domain and communicates to the transmitter a control signal indicative of one or more preferred channel components or a magnitude of one or more channel component coefficients, or both, in quantized form. The transmitter receives the control signal and constructs a beam pattern in the transform domain using the information received from the receiver.

The invention discloses a method, device and system for transmitting demodulation reference signals (DMRSs), for solving the problem that the orthogonality of each UE pilot frequency cannot be ensued when multiple UE is simultaneously accessed in the prior art. The method provided by the embodiments of the invention comprises: according to a correspondence table of an antenna port and a transmission layer number, respectively selecting a correspondence provided with the same transmission layer number as each UE for at least two UE which performs MU-MIMO communication at the same resource, and respectively distributing the antenna ports in each selected correspondence to the corresponding UE, the different antenna ports being distributed to the different UE; and notifying the corresponding UE of the index numbers of the selected correspondence, and sending the DMRSs through the antenna ports in the selected correspondence. According to the embodiments of the invention, the orthogonality of the DMRSs of multiple simultaneously accessed UE can be ensured, the system capacity is enhanced, simultaneous access of UE with multiple different transmission layer numbers can be supported, and the system flexibility is improved.

A solution for multiple base station collaborative communication in TDD (Time Division Duplex) and FDD (Frequency Division Duplex) systems is provided. To be specific, a serving base station and coordinating base station transmit detection signals with specific Multiple Input Multiple Output (MIMO) features on one or more communication resources. The mobile station measures the detection signals on the one or more communication resources and generates indication information of the recommended collaborative communication modes based on the measurement results. Preferably the indexes of the time-frequency resources corresponding to the recommended collaborative communication modes are reported to the serving base station. Then the serving base station schedules at least one of the one or more mobile stations according to the indication information reported by the one or more stations and provides MIMO communication manner for the mobile station scheduled. The coverage of the cells is improved, the cell edge user throughput is increased and the inter-cell interference between neighboring base stations is decreased by exploiting the invention. Preferably the amount of uplink feedback information is decreased and the uplink bandwidth is saved.

A multi-input-multi-output (MIMO) communications system is provided for conveying signals over a MIMO channel. The system includes a precoder for precoding a signal based upon a uniform channel decomposition scheme. The system further comprises a transmitter in communication with the precoder for conveying the precoded signal over a subchannel of the MIMO channel.

Multiple-input-multiple-output (MIMO) timing recovery. A novel approach is presented to perform timing recovery when processing the multiple received signals within a MIMO communication device. This may be implemented for a singular received signal, or a plurality of received signal streams. In addition, this timing recovery may be performed in conjunction with carrier detection to provide more robust performance. Alternatively, indicia and / or signals corresponding to carrier detection of these signals may be provided to timing recovery functionality from carrier detection functionality external to the timing recovery functionality. Certain processing and analysis is performed on a modified correlation function that is generated using samples of moving windows that pass over symbols of a packet. Based on this analysis of the modified correlation function, and sometimes in conjunction with one or more carrier detect signals, timing recovery may be performed thereby locating the point at which decoding of the packet may be performed.

Data is transmitted over multiple input multiple output (MIMO) channels. Plural bit streams are modulated into multiple data symbol vectors. Each vector has a transmission rank with one vector for each MIMO channel. Transmission rank is the number of elements in a data symbol vector corresponding to the number of data streams being transmitted in parallel over each MIMO channel. The multiple data symbol vectors are preceded into multiple precoded symbol vectors using a plurality of precoder cycling sets, one set for each transmission rank including multiple different precoders. The precoders in each precoder cycling set are well-separated with respect to a plurality of distance measures. The precoding includes precoding each data symbol vector of a transmission rank with a precoder belonging to the precoder cycling set of that transmission rank. The precoded symbol vectors are then transmitted over the MIMO channels.