776 results about "Broadband wireless communications" patented technology

A method for performing a handover by a subscriber station (SS) in a broadband wireless communication system including a serving base station (BS) communicating with the SS, and at least one neighbor BS neighboring the serving BS. The SS receives downlink signals from the serving BS and the neighbor BS; measures an arrival time difference between the downlink signal received from the serving BS and the downlink signal received from the neighbor BS; and transmits the measured arrival time difference to the serving BS.

The system and method for standoff detection of human carried explosives (HCE) is a portable system that automatically detects HCE up to a range of 200 meters and within seconds alerts an operator to HCE threats. The system has radar only, or both radar and video sensors, a multi-sensor processor, an operator console, handheld displays, and a wideband wireless communications link. The processor receives radar and video feeds and automatically tracks and detects all humans in the field of view. Track data continuously cues the narrow beam radar to a subject of interest, the radar repeatedly interrogating cued objects, producing a multi-polarity radar range profile for each interrogation event. Range profiles and associated features are automatically fused over time until sufficient evidence is accrued to support a threat / non-threat declaration hypothesis. Once a determination is made, the system alerts operators through a handheld display and mitigates the threat if desired.

Disclosed are a system for transmitting data using a band AMC in a broadband wireless orthogonal frequency multiplexing access system and a method thereof. In a broadband wireless communication system, a method for allocating data bursts to a mobile subscriber station according to channel state in a broadband wireless communication system, the method including transmitting allocation information to the mobile subscriber station, the allocation information including information about a sub frequency band containing the data bursts allocated to the mobile subscriber station and information about the number of band AMC subchannels allocated to the mobile subscriber station in the sub frequency band and receiving the data bursts from the mobile subscriber station according to the allocation information.

A method for controlling errors in a wireless link layer using a simultaneous multiple copy scheme and an adaptive forward error correction (FEC) scheme in a wideband wireless communication is provided. The method for controlling errors in a link layer in wideband wireless communication using an automatic repeat request (ARQ) scheme, in which a wideband wireless channel is used for communication between a first node and a second node, includes the steps of (a) estimating the error ratio of a forward (a direction in which a cell is transmitted from the first node to the second node) channel using the state of a backward (a direction in which a cell is transmitted from the second node to the first node) channel, and transmitting a cell, in which a forward error correction (FEC) code having an encoding ratio that varies depending on the estimated error ratio is included in a protocol data unit (PDU) of a wireless link layer, through the forward channel and (b) re-transmitting the copy of a cell transmitted in the step (a), when feedback information that indicates that an error exists in the cell transmitted in the step (a) is received through the backward channel. It is possible to reduce the number of times of re-transmission by improving the probability of correcting forward errors using more error controlling bits as the state of the channel is worse and to minimize the waste of resources using less error controlling bits as the state of the channel is better, to thus obtain the optimal performance and guarantee the minimum delay time.

An apparatus and method for transmitting / receiving an random access channel (RACH) signal in a broadband wireless communication system where a total uplink frequency band is divided into M sub-bands are provided. In the RACH transmitting apparatus, a generator generates an access code. A sub-carrier allocator divides the access code into M sub-blocks and allocates each of the M sub-blocks to successive sub-carriers in a sub-band. An inverse fast Fourier transform (IFFT) processor generates an orthogonal frequency division multiplexing (OFDM) symbol by performing an IFFT on the allocated sub-blocks.

A software platform in an Internet Protocol (IP) phone having the ability to be used with different communication infrastructures such as broadband, wireless communication and Plain Old Telephone System (POTS) service. Further, the software platform in the IP phone has the ability to be used with different applications operating on the IP phone. Further, the IP phone has the ability to perform additional functionality than traditional Public Switched Telephone Network (PSTN) phones, such as searches advertising, given its ability to converge voice and data within a single terminal.

Disclosed is a method for enabling a mobile station existing in a serving cell area to perform a handover procedure in a broadband mobile communication system including the mobile station, a serving base station providing a service to the mobile station, and one or more target base stations containing at least one target cell area overlapping with the serving cell area occupied by the serving base station. The method includes transmitting a handover request message from the mobile station to the serving base station when it is detected that a performance of a handover is necessary; and transmitting a handover indication message containing handover cancel information to the serving base station when the mobile station determines a cancel of the handover while the mobile station is being handed over to one or more target base stations by the serving base station.

A system and method for transmitting control information and data to a mobile station in a communication system using adaptive antenna technology defined in a broadband wireless communication system. In a method for transmitting and receiving information data in the wireless communication system, a base station separates information data to be transmitted into control information and user data, applies different modulation and coding schemes to the control information and the user data, and transmits the information data to an associated mobile station. The mobile station identifies the modulation and coding schemes of the information data received from the base station and demodulates a total of the information data according to the modulation and coding schemes, or independently demodulates the control information and the data according to the modulation and coding schemes.

This present invention includes an indoor unit (IDU) and compact outdoor unit (ODU) having an intermediate frequency / modem circuit, millimeter wave transceiver circuit, and digital interface between the IDU and the ODU capable of up to about 100 MBps data rate over at least about a 300 meter cable. The system uses a conversion to the polar coordinate system completes calculations in the polar coordinate system, reducing the computational requirements, and therefore, the size and cost of the system.

An apparatus and method for processing a vertical handoff between a WLAN and a broadband wireless communication network are provided. In a method of processing a vertical handoff in a handoff processor having a mapping table in which QoS information for the broadband wireless communication network is mapped to QoS information for the WLAN, QoS information about an STA received from a source network is converted to QoS information suitable for a target network, referring to the mapping table. A message containing the converted QoS information is generated and sent to the target network.

The present invention relates to broadband wireless communication using multiple carrier frequencies, and the selection or allocation of those frequencies. The invention is particularly but not exclusively related to ultra wideband (UWB) technologies. The present invention provides a method of dynamically selecting carrier frequencies for carrying a broadband channel, the method comprising: allocate a group of carrier frequencies for carrying the broadband channel; identify a number of alterative groups of carrier frequencies; monitor channel performance of the broadband channel for the allocated group of carrier frequencies; re-allocate the broadband channel to be carried by one of the alternative groups of carrier frequencies in response to the monitored channel performance degrading below a threshold.

A method for transmitting a preamble over a Random Access CHannel (RACH) in a wireless communication system is provided. The method includes generating a preamble having a length longer than a basic transmission unit, and dividing the preamble into preambles having a length less than the basic transmission unit; and sequentially transmitting the divided preambles over the RACH using different antennas.

A communication network architecture including a broadband radio access network is provided. The architecture includes a terminal for transmitting an application layer service request message to request a service, a Policy Charging Rule Function (PCRF) for generating Quality of Service (QoS) parameters of an Internet Protocol (IP) layer using QoS parameters of an application layer contained in the application layer service request message, a first Policy Decision Function (PDF) for generating one or more QoS parameters of the IP layer in addition to the IP layer QoS parameters generated at the PCRF and a second PDF for generating a QoS parameter set of a radio access network using the IP layer QoS parameters generated at the PCRF and the one or more IP layer QoS parameters generated at the first PDF. The communication network guarantees an end-to-end QoS.

Disclosed is a method for transmitting a reference signal, in a method for transmitting a Channel State Information-Reference Reference Signal (CSI-RS) for measuring a transmission channel according to each antenna and a data signal in a broadband wireless communication system based on a MIMO scheme through a plurality of antennas.

An apparatus and method for canceling ISI in a broadband wireless communication system are provided. In a transmitter of the broadband wireless communication system, a controller acquires a CP length, a puncturing pattern, and a time sample interval according to a delay spread. A puncturer punctures coded data in the puncturing pattern. An IFFT processor IFFT-processes the punctured coded data and outputs sample data. A CP inserter generates an OFDM symbol by inserting a copy of a last part of the sample data before the sample data. Here, the length of the last part of the sample data is equal to the CP length. A D / A converter converts the OFDM symbol to an analog signal at a sampling rate determined by the time sample interval.

A method for transmitting burst allocation information by a base station in a broadband wireless communication system in which a transmitted frame includes symbols, and orthogonal subcarriers in a frequency axis constitute each of the symbols based on a predetermined time unit. The method includes the steps of generating a reduced connection identifier (CID) by reducing a basic CID of a mobile terminal connected to the base station when the basic CID exists within a preset range, and inserting an MAP, which includes an enabled field representing the reduced CID and one of use and non-use of the reduced CID, into the frame, and transmitting the frame to the mobile terminal.

Wireless communications transceivers include a transmitter that is configured to selectively frequency shift and transmit portions of broadband information over multiple non-contiguous narrowband frequency bands / segments, each of which is too narrow to carry the broadband information. A receiver also is configured to receive and selectively frequency shift portions of broadband information from multiple non-contiguous narrowband frequency bands / segments, each of which is too narrow to carry the second broadband information. Broadband information thereby may be transmitted and received in a regulated communications environment, even though a given provider may only be assigned discontinuous frequency bands / segments, none of which is wide enough to carry the entire broadband information.

A communication system is disclosed that is comprised of a plurality of communication markets. Each communication market comprises a wireless control system. Each of the wireless control systems is configured to retrieve a general configuration file and a custom parameter file. The custom parameter file is customized for a geographic region. Each of the wireless control systems is configured to process the general configuration file and a custom parameter file to configure itself with a custom configuration. Each of the wireless control systems is then configured to control broadband wireless communications based on the custom configuration.

Disclosed is a method for allocating a reerence signal, in a method for transmitting a Channel State Information-Reference Reference Signal (CSI-RS) for measuring a transmission channel according to each antenna and a data signal in a broadband wireless communication system based on a multiple input multiple output (MIMO) scheme through a plurality of antennas.

An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.

A method and apparatus for transmitting a DL-WUCH for a mode transition in a sleeping state in a broadband wireless communication system are provided. In the broadband wireless communication system, a base station (BS) transmits control information to a plurality of subscriber stations (SSs) on a common control channel. To demodulate a control channel signal received from the BS, an SS receives a wakeup channel signal which indicates whether the control channel signal includes control information for the SS, reads a wakeup channel indicator at a predetermined position assigned to the SS of the wakeup channel signal, and determines whether to demodulate the control channel signal according to the wakeup channel indicator.

Methods and systems for interfacing between broadband wireless communication systems and Local Area Network (LAN) systems includes a repeater station placed at a location that receives sufficient signal strength from a broadband wireless service provider. LAN devices interface with the broadband wireless service provider through the repeater station. The LAN devices are able to operate within the operating range of the repeater station. The repeater station includes a protocol converter that interfaces between a first protocol associated with the broadband wireless service provider, and one or more protocols associated with the devices. For example, and without limitation, the protocol converter converts between a first protocol associated with a Wide Area Network (WAN) service provider, such as a cellular telephone protocol, and one or more LAN protocols associated with the one or more devices. The one or more devices optionally include one or more wireless devices.

An apparatus and method for operating a hierarchical cell in a wireless communication system are provided. A femto BS transitions into a sleep mode if there is no accessed MS for a predefined time. The femto BS transmits a FEMTO-ADV message in the sleep mode to notify of the presence of the femto BS. The femto BS releases the sleep mode upon receiving a MOB-FEMTO-AWAKE-REQ message from an MS receiving the FEMTO-ADV message. Thereafter, the femto BS communicates with the MS.

A method and apparatus for allocating bandwidth in a broadband wireless communication system is disclosed. One embodiment uses a self-correcting bandwidth request / grant protocol. The self-correcting bandwidth request / grant protocol utilizes a combination of incremental and aggregate bandwidth requests. CPEs primarily transmit incremental bandwidth requests to their associated base stations, followed by periodic transmissions of aggregate bandwidth requests. The use of periodic aggregate bandwidth requests (that express the current state of their respective connection queues) allows the bandwidth allocation method and apparatus to be “self-correcting”. Another embodiment utilizes an abridged bandwidth request / grant protocol to allocate bandwidth. The abridged bandwidth request / grant protocol system utilizes padding packets to request a reduction in bandwidth allocation to a CPE. A base station modem alerts a base station CPU when the BS modem receives a padding packet from a CPE. After alerting the BS CPU the method can reduce the associated CPE's bandwidth allocation.

Provided is a method for performing a ranging process in a broadband wireless communication system. In the method, a ranging request message is transmitted from a mobile station to a base station. A ranging response message including cause information of a ranging status is transmitted from the base station to the mobile station.

A method and apparatus for requesting and allocating bandwidth in a broadband wireless communication system. The inventive method and apparatus includes a combination of techniques that allow a plurality of CPEs to communicate their bandwidth request messages to respective base stations. One technique includes a “polling” method whereby a base station polls CPEs individually or in groups and allocates bandwidth specifically for the purpose of allowing the CPEs to respond with bandwidth requests. The polling of the CPEs by the base station may be in response to a CPE setting a “poll-me bit” or, alternatively, it may be periodic. Another technique comprises “piggybacking” bandwidth requests on bandwidth already allocated to a CPE. In accordance with this technique, currently active CPEs request bandwidth using previously unused portions of uplink bandwidth that is already allocated to the CPE. The CPE is responsible for distributing the allocated uplink bandwidth in a manner that accommodates the services provided by the CPE. By using a combination of bandwidth allocation techniques, the present invention advantageously makes use of the efficiency benefits associated with each technique.

An apparatus and method for supporting Peer-to-Peer (P2P) communications in a broadband wireless communication system are provided. A frame used by the terminal in P2P communications includes a plurality of P2P contention channels overlapping with a region for cellular communications and at least one P2P dedicated channel allocated by a base station only for the P2P communications. The method includes establishing a P2P connection with a correspondent terminal through the at least one P2P dedicated channel, and exchanging P2P communication data with the correspondent terminal through at least one of the plurality of P2P contention channels.

An Apparatus and a method for interference cancellation in a wireless communication system are provided. When a resource of an Interference Cancellation (IC) zone is allocated to a terminal traveling in a service coverage, resource allocation information relating to an IC zone of neighbor cells is gathered. Resource allocation information is generated relating to the resource allocated to the terminal comprising resource allocation information of the IC zone of the neighbor cells. The resource allocation information relating to the resource allocated to the terminal is transmitted to the terminal. Accordingly, when the interference is present, the interference cancellation is carried out to reduce the load on the terminal and enhance the reception performance.