4674results about "Site diversity" patented technology

A system and machine-implemented method are described for performing precoding interpolation in a DIDO system which employs orthogonal frequency-division multiplexing (OFDM) and DIDO precoding to communicate with a plurality of distributed-input-distributed-output (DIDO) clients. For example, a system according to one embodiment of the invention comprises: selecting a first subset of ODFM tones to determine a first subset of precoding weights; deriving a second subset of precoding weights for a second subset of ODFM tones by interpolating between the first subset of precoding weights; and using a combination of the first subset of precoding weights and the second subset of precoding weights to precode a data stream prior to transmitting the data stream to a DIDO client.

Methods and systems for dynamic spectrum access (DSA) in a wireless network are provided. A DSA-enabled device may sense spectrum use in a region and, based on the detected spectrum use, select one or more communication channels for use. The devices also may detect one or more other DSA-enabled devices with which they can form DSA networks. A DSA network may monitor spectrum use by cooperative and non-cooperative devices, to dynamically select one or more channels to use for communication while avoiding or reducing interference with other devices.

The present invention relates to wireless networks using relaying. In the method according to the present invention of performing communication in a two-hop wireless communication network, a transmitter 210, a receiver 220 and at least one relay station 215 are engaged in a communication session. The relay station 215 forwards signals from a first link between the transmitter 210 and the relay station 215 to a second link between the relay stations 215 and the receiver 220. The forwarding performed by the at least one relay station 215 is adapted as a response to estimated radio channel characteristics of at least the first link. Preferably the forwarding is adapted as a response to estimated radio channel characteristics of both the first and second link.

A distributed antenna system (DAS) includes a multiple-input and multiple-output (“MIMO”) base station configured to output at least a first and second signal, and a hybrid coupler coupled thereto, the coupler configured to receive the first and second signal from the MIMO base station on respective first and second ports and provide an output signal on at least one output port, the output signal including at least a portion of the first signal and at least a portion of the second signal. The DAS further includes a master unit communicating with the coupler and configured to receive at least the output signal, and at least one remote unit communicating with the master unit and configured to communicate the output signal to a device.

A method for managing mobility of a terminal in a heterogeneous network environment is provided. According to an aspect, there is provided an operation method of a terminal receiving parameters for Coordinated Multi-point transmission/reception (CoMP) operation in a heterogeneous network environment, the operation method including, at the terminal, receiving at least one parameter among a CoMP operation mode parameter, a time information parameter regarding a time at which the CoMP operation starts, a point information parameter about points that participate in the CoMP operation, and a CoMP operation parameter, from a base station, through a layer-3 message. Therefore, it is possible to avoid an unnecessary ping-pong handover and efficiently provide service continuity.

A method and system for cooperative multiple-input multiple output (MIMO) transmission operations in a multicell wireless network. Under the method, antenna elements from two or more base stations are used to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions to and from one or more terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.

Two-way (full-duplex) wireless communications. Various embodiments measure interference channels and provide for interference cancellation in both analog and digital domains to mitigate self-interference. The system supports multiple clients wherein new clients can join the network asynchronously, and also supports Multiple-Input Multiple-Output (MIMO) antennas.

The present invention relates to relay supported wireless communication to enhance communication performance. In the wireless communication system according to the invention neighboring relay stations are arranged with substantially overlapping coverage. In the method according to the invention mobile stations makes soft association to relay stations. The mobile stations feed back the selection of relay stations and channel quality measures to the base station. The base station adapts the transmission to the relay stations based on each mobile stations reported soft associations and channel quality measures. In this way the control signaling to and from the relay stations can be very limited.

There is provided a method for configuring a power distribution within a cellular network system. The cellular network system includes at least one cooperation area. The at least one cooperation area is defined by at least two base stations, each including at least one antenna, wherein each base station has at least one beam. The method includes configuring the base stations to transmit at a first transmit power level for providing a first receiving power level for a user equipment at a center region of the cooperation area, and configuring the base stations to transmit at a second transmit power level for providing a second receiving power level at a border region of the cooperation area, wherein the second receiving power level is lower than the first receiving power level.

A communication method uses a distributed cell-free network of spatially independent service antennas. According to the method, pilot sequences are allocated to a user population of access terminals by an allocation procedure that imposes local relative orthogonality of pilot sequences. Channel coefficients for access terminals arc determined by measuring allocated pilot sequences as received by each of the service antennas. In embodiments of the invention, the determination of channel coefficients is performed independently and the resulting channel coefficients are locally stored at the respective service antennas. At each service antenna, a processor independently uses locally stored channel coefficients to precode forward link signals or to at least partially decode reverse link signals.

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.

A multiple antenna system including a mobile station and a base station are operable to perform a method for transmitting control information for interference mitigation. A Mobile Station (MS) can transmit control information for interference mitigation. The MS determines a first Precoding Matrix Index (PMI) and a second PMI for interference from an adjacent Base Station (BS). Based on a correlation level from correlation values between one of the first PMI and second PMI and the remaining PMIs in the codebook, the MS determines a level of a subset of PMIs, and feeds back information indicating the correlation level.

A frequency translating repeater (250) for use in a time division duplex radio protocol communications system includes a processor (260), a bus (261), a memory (262), an RF section (264), and an integrated station device (264). An access point (210) is detected based on information transmitted frequency channels using a protocol. Detection is initiated automatically during a power-on sequence or by activating an input device such as a button. Frequency channels are scanned for a beacon signal and an access point chosen as a preferred access point based on a metric such as power level.

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.

The embodiment of the invention relates to the field of communication technology and discloses a data flow transmission method and a related equipment and a system, wherein the data flow transmission method comprises the following steps: a first network link and a second network link are established between a network side and user equipment; the first network is different from the second network; the user equipment associates the first network link to the second network link; and according to a scheduling algorithm, the user equipment distributes the same data flow into the first network link and the second network link for transmitting. The embodiment of the invention can realize mixed transmission with the same data flow in different networks. Compared with the existing schemes, the embodiment of the invention can carry out distributary more flexibly and improve the service quality.

A method for using buffer occupancy in uplink scheduling for a communication device includes a first step of sending buffer occupancy information and a time stamp indicating a last transmission opportunity provided to the communication device to an active set base stations. A next step includes utilizing the buffer occupancy information and time stamp to adjust a scheduling fairness setting for the communication device. A next step includes receiving scheduling information from a scheduler in accordance with the scheduling fairness setting. A next step includes transmitting on an uplink channel in accordance with the scheduling information.

A virtual cell management apparatus and method using sectors in an orthogonal frequency division multiplexing mobile communication system including a cell structure having cells each comprised of a plurality of sectors, the cells performing data communication with mobile terminals within a corresponding cell through at least one subchannel having orthogonality. The method comprises forming a virtual cell with a particular one of sectors constituting a particular cell and sectors of two other cells neighboring the particular sector; transmitting, by three base stations forming the virtual cell, an interference measurement value and a channel parameter estimation value from a mobile terminal located in the virtual cell to a base station controller that controls the virtual cell, thereby allocating wireless resource including frequency bandwidth, initial bits, subcarriers and refined bits in the virtual cell; transmitting the allocated wireless resource to the three base stations so that the base stations allocate a same subchannel to each mobile terminal located in the virtual cell; and transmitting same data over the allocated subchannel.

The present invention discloses a distributed base station serving mobile stations, which comprises multiple antenna-RF processing units and a central processing unit remotely connected with said multiple antenna-RF processing units. Each of the antenna-RF processing units has an antenna array formed by multiple antennas. Said central processing unit comprises: an MIMO coding unit for MIMO coding of data of each of the mobile stations so that data of each of the mobile stations generates multi-path data symbols; a beam-forming unit for multiplying each path data symbol of the multi-path data symbols of each of the mobile stations by a weighted coefficient vector corresponding to this path data symbol, to obtain beam-forming data of each path data symbol of each of the mobile stations; and an overlapping unit for, with respect to each antenna in said antenna-RF processing units, overlapping beam-forming data of the respective mobile stations for this antenna and feeding the overlapped beam-forming data to this antenna for transmission. The present invention further discloses a communication system having the above distributed base station and the corresponding signal transmission method.

Provided are a method and apparatus for transmitting/receiving data by using a multi-path. The multi-path is established between two transceivers, data is transmitted via each path at a predetermined time, a data receipt acknowledge control signal ACK of each path is received, and a path by which the data receipt acknowledge control signal ACK is not received is determined. Therefore, the path by which the data receipt acknowledge control signal ACK is not received is not used any further but data is transmitted via a path by which the data is previously transmitted, so that the data can be transmitted even if a line of sight (LOS) of the two transceivers comprising a directional antenna is blocked by a person or an obstacle.

The soft handoff in an OFDMA system. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone have subcarriers with a subchannel definition, for example, an identical permutation.