Abstract: A new random linear network coding scheme for reliable communications for time division duplexing channels is proposed. The setup assumes a packet erasure channel and that nodes cannot transmit and receive information simultaneously. The sender transmits coded data packets back-to-back before stopping to wait for the receiver to acknowledge (ACK) the number of degrees of freedom, if any, that are required to decode correctly the information. Provided herein is an analysis of this problem to show that there is an optimal number of coded data packets, in terms of mean completion time, to be sent before stopping to listen. This number depends on the latency, probabilities of packet erasure and ACK erasure, and the number of degrees of freedom that the receiver requires to decode the data. This scheme is optimal in terms of the mean time to complete the transmission of a fixed number of data packets.

Abstract: A space-based component, such as a satellite, is configured to receive wireless communications from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency, and to transmit wireless communications to the radiotelephones over a downlink radiotelephone frequency. An ancillary terrestrial network, that may include one or more ancillary terrestrial components, is configured to transmit wireless communications to, and receive wireless communications from, the radiotelephones over the uplink satellite radiotelephone frequency in a time-division duplex mode.

Abstract: There is described an apparatus and method for implementing a communications port. The apparatus comprises a core, which is operable to divide the port into a plurality of sub-ports by dividing a data transfer capacity of the port among the plurality of sub-ports using time division multiplexing. Each sub-port is allocated a corresponding data transfer capacity.

Abstract: A system for providing bidirectional communication for a data bus includes a datalink interface component configured to interface into a datalink. The datalink interface component is configured to operate in at least one of a first data communication state, a second data communication state, and a wholly inactive state. The first data communication state causes a first data communication component to communicate via the datalink interface and a second data communication component to be in an inactive state. The second data communication state causes the first data communication component to exist in an inactive state and the second communication component to communicate via the datalink interface. The wholly inactive state causes the first and second data communication components to exist in the inactive state.

Abstract: A cellular communication system comprises first and second serving communication units supporting respective first and second time division duplex (TDD) modes of operation on respective first and substantially frequency-adjacent second frequency channels comprising a plurality of uplink transmission resources divided into uplink timeslots and a plurality of downlink transmission resources divided into downlink timeslots. The first and second modes of TDD operation are dissimilar and communications cover substantially the same or overlapping geographic area. The first serving communication unit transmits a plurality of idle periods in the first mode of operation arranged to encompass a time period used by the second serving communication unit for switching communication between downlink and uplink transmissions of the second mode of operation.

Abstract: A system comprises a first unit and a second unit communicatively coupled to the first unit. The first unit is operable to receive a first original radio frequency signal and the second unit is operable to receive a second original radio frequency signal. The first and second original radio frequency signals are originally transmitted on a radio frequency channel using time division duplexing. The first unit communicates a control signal to the second unit, the first unit generating the control signal based at least in part on detecting when the first original radio frequency signal is being received at the first unit. The second unit uses the control signal to determine when to output a first reproduced radio frequency signal in accordance with the time division duplexing used to originally transmit the first and second original radio frequency signals on the radio frequency channel. The first reproduced radio frequency signal is derived from the first original radio frequency signal.

Abstract: A method of determining a boundary of a subframe in a time division duplexing (TDD) system is provided. The method detects a power level of a signal on at least one radio frequency, the signal comprising at least one subframe. A time-domain correlation is done on the detected signal with a first reference signal, wherein the first reference signal represents at least one subframe. The location in time of a boundary of the at least one subframe of the detected signal is determined based on the correlation of the detected signal and the first reference signal.

Abstract: Methods and systems for TDD hum noise cancellation are disclosed and may include correlating a received audio signal to a time division duplexed (TDD) envelope signal, controlling a feedback signal based on the correlating, and cancelling a TDD noise signal via the feedback signal. The amplitude and delay of the feedback signal may be configured for controlling. A least mean square (LMS) filter may be utilized for the correlating and may include a finite impulse response filter. The TDD envelope signal may be generated on the chip or may be received from a source external to the chip. The feedback signal may be added to the received audio signal for the cancelling.

Abstract: A broadband local area data network uses coaxial cable wiring for interconnection of terminal devices. Orthogonal frequency division multiplexing (OFDM) with bit loading is used to overcome channel impairments and provide a path for terminal devices to transmit to and receive from other terminal devices. Probe messages are sent between devices to characterize the communication channel and determine optimum bit loading. The data network shares the cable spectrum with other services and uses frequency bands not used by other services. Adaptive power control can be used to maintain signal to noise ratio in a communication between terminal devices. Frequency coordination can be used to avoid interference between the LAN communications and other services transmitted on the cable.

Abstract: A communications network comprising a plurality of first stations and a plurality of second stations, said first stations being arranged to communicate with the second stations, said first and second stations being arranged so that each of said first and second stations receives signals and transmits signals at different times, wherein at least two of said first stations are arranged to transmit at the same time and to receive at the same time and at least two of said first stations are arranged so that at least one of said first stations transmits and receives at the same time as at least one of the first stations receives and transmits respectively.

Abstract: A time division duplex (TDD) wireless apparatus includes a low noise amplifier (LNA) system, at least one antenna and a transceiver system. The apparatus supports N time division duplexed channels which each have a transmit direction of transmission flow and a receive direction of transmission flow. The LNA system comprises N sub-units. Each sub-unit comprises a first circulator for connecting to a respective TX/RX feed to the transceiver system and a second circulator for connecting to the at least one antenna. The first circulator and second circulator within each sub-unit are interconnected to provide a path in one of the directions of transmission flow. The first circulator of each sub-unit is connected to the second circulator of another sub-unit to provide a path in the other direction of transmission flow. A single channel variant is also provided.

Abstract: Techniques are provided to facilitate the computation of beamforming weights used by a first communication device when sending a transmission via a plurality of antennas to a second communication device where knowledge of the behavior of the channel between the first communication device and the second communication device is limited to a portion of a wide frequency band. A frequency extrapolation beamforming weight computation process is provided to derive knowledge in other frequency subbands based on information contained in the received transmission from the second communication device.

Abstract: Apparatus and methods for updating symbol information in a communication device with hardware such as a microcontroller are disclosed. The disclosed apparatus and methods employ waiting for the beginning of a symbol in a sample stream at a predetermined time. One or more programmed instructions are read at the beginning of the symbol, and then symbol information is updated based on the one or more programmable instructions and setting a time for a beginning of a next symbol. The programmed instructions consist of instruction code words that are executed by a dedicated microcontroller or similar hardware, which affords flexibility for updating symbol information, particularly for multimode communication devices operable across multiple communication technologies.

Abstract: A multiple-input-multiple output (MIMO) transmitter for transmitting a group of sequential orthogonal frequency division multiplexed (OFDM) symbols on a time-division duplexed (TDD) channel in accordance with an IEEE 802.16 standard using a plurality of antennas. The MIMO transmitter comprises a spatial-frequency parser to parse a block of bits into spatial-frequency blocks of a variable number of coded bits, and subcarrier modulators to individually modulate OFDM subcarriers with the spatial-frequency blocks in accordance with spatial-frequency subcarrier modulation assignments to generate groups of symbol-modulated subcarriers. The TDD channel comprises a plurality of the groups of the OFDM subcarriers, and the OFDM subcarriers within each group of subcarriers and within each group of sequential OFDM symbols have the same spatial-frequency subcarrier modulation assignments.

Abstract: An apparatus for maintaining synchronization with a plurality of asynchronous communication links includes a first counter that generates a first local network clock, and a second counter that generates a second local network clock. The apparatus also includes an offset controller coupled with the first counter and coupled with the second counter, the offset controller configured to load a current network clock value of a first network clock of a first communication link into the first counter, and to load a current network clock value of a second network clock of a second communication link into the second counter. The apparatus further includes a drift controller coupled with the first counter and with the second counter, the drift controller configured to correct a drift between the first local network clock and the first network clock and to correct a drift between the second local network clock and the second network clock.

Abstract: A system and method for generating a flexible time slot in an internal voice mail system, the system includes: a first counter/time slot playback device operating as a counter in response to a system synchronization signal and outputting at least one time slot (TS) signal; a second counter/time slot playback device operating as a counter in response to the system synchronization signal and outputting at least one time slot (TS_n) signal; a transmit start of transfer (TSX) channel synchronization generator generating a proper TSX channel synchronization signal in response to channel information data transmitted from the voice mail system; and a flexible TSX generator outputting a TSX signal corresponding to a channel synchronization data value selected and transmitted by the TSX channel synchronization generator after synthesizing the signals output from the first counter/time slot playback device and the second counter/time slot playback device and generating at least one synchronized TSX signal.

Abstract: A time division duplex (TDD) user equipment (UE) is configured to synchronize to a TDD base station. The UE includes a receiver configured to receive a primary synchronization code along with a plurality of secondary synchronization codes from a TDD base station. The TDD base station is associated with having a code group out of N code groups. The plurality of secondary synchronization codes number less than (log2N)+1 and are quadrature phase shift keying modulated. The UE also includes a corresponding matched filter to each of the received secondary synchronization codes. The UE is configured to identify the code group of the TDD base station by the received plurality of secondary synchronization.

Abstract: A receiving device which received segments out of sequence identifies a lost segment among the segments to be received successively and transmits an acknowledgement including the number of lost segments as an advertised window size. By substituting either one of a transmitting device or a receiving device included in a communication system with a transmitting device or a receiving device of the present invention, a segment retransmission method according to the present invention is achieved. The present invention thus allows a conventional communication system to perform the lost segment retransmission of the present invention.

Abstract: A device and method for communicating by a mobile communication terminal in communication with a base station. The method according to an embodiment includes exchanging a frame of data with the base station. The frame of data includes a) a plurality of first subframes each having a first number of orthogonal frequency division multiple access (OFDMA) symbols, and b) a plurality of second subframes each having a second number of orthogonal frequency division multiple access (OFDMA) symbols different from the first number. A first and a last subframe each includes one of the plurality of first subframes.

Abstract: The present invention relates to a method for referencing a physical channel carrying point-to-multipoint service data in a wireless communication system. The present invention utilizes an identifier to reference specific physical channel configurations previously sent to a mobile terminal from a network. The identifier may reference an entry in a list of physical channel configuration in a specific message. Alternatively, a physical channel configuration in a first message is first allocated a specific identity. Then, a specific identifier referencing the specific identity is used in a second message to identify the physical channel configuration in the first message.

Abstract: A device and method for communicating by a mobile communication terminal in communication with a base station. The method according to an embodiment includes exchanging a frame of data with the base station. The frame of data includes a) a plurality of first subframes each having a first number of orthogonal frequency division multiple access (OFDMA) symbols, and b) a plurality of second subframes each having a second number of orthogonal frequency division multiple access (OFDMA) symbols different from the first number.

Abstract: A method of providing uplink and downlink transmissions between a mobile terminal and a base station in a mobile communication system is provided. The method increases the flexibility and efficiency of a mobile communication system utilizing one or more relay entities and provides new frame structures to support legacy and new transmissions in a mobile communication system.

Abstract: There is provided a transmitter receiver apparatus in which a directional coupler and single pole double throw (SPDT) switches are includes on the reception side. In the directional coupler, a reception signal is inputted and split into two signals having phases different from each other by 90° and the two split signals are outputted to SPDTs. Each of the SPDTs outputs each of the split signals to an output terminal connected to an amplifier during a passage mode and to a terminal terminated with a predetermined impedance during a blocking mode.

Abstract: In one embodiment, the present invention includes a repeating frame for a time division radio communications system with a sequence of uplink slots each having a predetermined duration, a sequence of downlink slots, each having a predetermined duration that is greater than the duration of the uplink slots, an interburst guard time between each uplink slot, an interburst guard time between each downlink slot, and an interframe guard time after the sequence of downlink slots.

Abstract: A dynamic channel allocation method and system for use in a wireless network operates by monitoring at least the allocated channel allocated to a particular network node to generate one or more channel metrics relating to radio conditions on the channel. The metrics generated are Received signal power, signal to noise ratio of transmissions on the network and long-term mean square of the equaliser error used in each terminal. The generated metrics are communicated back to the cell access point or the network control server over a signalling channel, and a new frequency is allocated to the cell if it is determined from the metrics that the presently allocated channel is suffering interference. The signalling channel is preferably an ATM VPI/VCI pair, such that signalling messages are transmitted as ATM cells which can be communicated across the wireless channel using the sane signalling frame as is used for payload cells.

Abstract: An apparatus and method for compensating for nonlinearity of a portable communication terminal are provided. The apparatus includes a modem for modulating Transmission (Tx) data, a Digital Pre-Distortion (DPD) mode controller for obtaining power level information and for determining a power on/off state of a DPD unit by using the obtained information in the Tx mode, and the DPD unit for outputting the modulated data input from the modem without performing a DPD operation when power is off, and for outputting the modulated data input from the modem by performing the DPD operation when power is on.

Abstract: A mobile communication system includes a base station connected to a backbone network, and a mobile station configured to communicate with the base station using a radio frequency. The system has a first communication mode, in which a first radio frequency is used for an uplink and a second radio frequency is used for a downlink; a second communication mode, in which the first radio frequency is used for the uplink, and the second radio frequency is shared by the uplink and the downlink; a third communication mode, in which the second radio frequency is used for the downlink, and the first radio frequency is shared by the uplink and the downlink; and a mode switcher configured to switch the first through third communication modes in accordance with data transfer volumes on the uplink and the downlink.

Abstract: Disclosed is an apparatus and a method for controlling automatic gain in a wireless communication system using a Time Division Duplex (TDD) scheme. The apparatus comprises a power detecting unit for detecting a power of a TDD frame signal on a receive path; an Automatic Gain Control (AGC) synchronizing signal generating unit for generating an AGC synchronizing signal enabled or disabled either during a Down Link (DL) frame or during an Up Link (UL) frame of a TDD frame; an automatic gain calculating unit for calculating a gain control value based on the power detected by the power detecting unit either during the DL frame or during the UL frame of the TDD frame in response to the AGC synchronizing signal; and an AGC unit for performing gain control for the TDD frame signal on the receive path on the basis of the calculated gain control value. Hence, as AGC is performed during only an actual receive frame, the optimized demodulation performance can be maintained.

Abstract: Method and apparatus employed by a UE for interference signal code power noise variance estimation employing a reduced number of samples utilizing the equation ? ^ n 2 = T · ? i = 1 N sample ? ? h n ? ( i ) ? 2 , where T = G · ? ? ( r ) N sample , where Nsample=Lchest?Npl·Kmax, where ? ? ( r ) = [ 1 + ( 1 r - 1 ) · ln ? ( 1 - r ) ] - 1 and where r = N sample L chest . As an alternative, a recursive technique may be employed wherein the noise variance is estimated from the ignored coefficients of the estimated channel output and upgraded recursively as per the following: ? ^ n 2 = 1 KW ? ? j = 1 K ? ? i = 1 W ? ? h i ( j ) - h ^ i ( j ) ? 2 , where ?i(j) are the channel estimates after the post processing and the noise variance estimates {circumflex over (?)}n?12, and the initial values of ?i(j) are all zeros.

Abstract: An RF module adapted for direct surface mounting to the top surface of the front end of the motherboard of a wireless base station such as, for example, a femtocell. The module comprises a printed circuit board having a plurality of direct surface mounted electrical components defining respective signal transmit and receive sections for RF signals. The signal transmit section is defined by at least a power amplifier, a coupler, and a lowpass filter. The signal receive section is defined by at least a receive bandpass filter and a low-noise amplifier. A lid covers selected ones of the electrical components except for at least the power amplifier. An RF switch is located between and interconnects the respective transmit and receive sections to an antenna pin.

Abstract: A method and apparatus for use in a wireless communication system to detect frequency division duplex (FDD) or time division duplex (TDD) after the radio timing and cell group ID have been determined from the S-SyS during a cell search, by correlating reference symbols (RSs) and detecting whether the RSs are on resource elements corresponding to FDD or TDD. By correlating the known RS, which is known after the cell ID is detected, to the assumed RS positions for FDD or TDD, the duplex form is detected.

Abstract: Communicating between stations in a network is described. A plurality of stations coordinate according to a distributed protocol to select a first station to transmit over a shared medium. The communication includes transmitting between the first station and a second station over the shared medium during a time period in which stations other than the first and second stations refrain from transmitting over the shared medium. The first station transmits information that grants permission to the second station to transmit during the time period.

Abstract: An apparatus and a system, as well as a method and article, may operate to select a group of contiguous communications channels having a specified number of channels, a center channel, and a control channel. Some embodiments may operate to select a group of contiguous communications channels having a specified control channel and a signed extension channel offset.

Abstract: A digital video interface system and method for communicating digital video data from a source device to a sink device is provided, where the clock channel is used to transmit data as well as clock signals in a bi-directional, half-duplex manner using time division multiplexing. The digital video interface system comprises one or more data channels configured to transmit digital video data from the source device to the sink device in time divisional multiplexing including a plurality of first time slots and second time slots, and a clock channel configured to transmit a clock signal from the source device to the sink device in the first time slots and configured to transmit additional data from the source device to the sink device or from the sink device to the source device in the second time slots.

Abstract: The present invention relates to a method, apparatus, system and computer program product, wherein a time division multiplex signal is received with a periodic first time period allocated to a downlink transmissions and a periodic second time period allocated to uplink transmissions. A decision time metric is obtained by correlating the received signal with a replica signal in order to detect a synchronization pattern provided in the first time period. Then, a slide window based normalization with a time window long enough to accommodate said second time period is applied to the decision time metric.

Abstract: A digital subscriber line transmission (xDSL), system includes a transmitting side which transmits training symbols by adding some data that is contained in a training symbol sequence onto at least one of the beginning and the end of this symbol sequence and then transmits the training symbol sequence. A receiving side removes the data that has been added onto the training symbol sequence and executes training processing. The length of the training symbol sequence and of a transmit symbol sequence at time of normal communication is set in such a manner that the symbol sequence will not fall within an interval in which effects of near-end crosstalk from a neighboring line are received. The data added to the training symbol sequence specifies an interval in which effects of the crosstalk are received.

Abstract: There is provided a communication apparatus that includes: a data communication unit which performs half-duplex communication of video frame data with an external device on a video frame-by-video frame basis, a switching unit which switches a transmission direction in which the data communication unit transmits the video frame data, a first control unit which controls the data communication unit to include a start command in the video frame data and send the video frame data, as well as controls the switching unit to switch the transmission direction in response to completion of the sending of the video frame data that includes the start command, and a second control unit which controls the switching unit to switch the transmission direction in response to completion of the reception of the video frame data that includes the start command.

Abstract: The invention relates to the field of signal processing for telecommunications, and concerns a method and receiver for processing a multi-user signal.

Abstract: A method to support dissymmetry service for multicarrier time division duplexing mobile communication system, which contains adopting different uplink and downlink time gap conversion point to support dissymmetry service among multicarrier frequency of different cells and same cell, when the original configured uplink and downlink time gap ratio can not support the service request, then changing the time gap ratio to receiving said request, adjusting service to avoid interference by quick dynamic channel distribution technology, in ending request service, changing time gap ratio in original ratio. Said invention supports different uplink and downlink time gap conversion point, the base station equipment needs establishing isolated uplink and downlink.

Abstract: A method of transmitting a data stream over a communication channel, the method comprising: providing symbol sets having different numbers of symbols; modulating data in the data stream that warrant different degrees of protection against noise onto symbols from symbol sets having different numbers of symbols, wherein which symbol set given data in the stream is modulated onto is independent of symbol sets onto which other data in the data stream is modulated onto; and transmitting the symbols.

Abstract: A memory architecture for a disk drive system in which Synchronous Random Access Memory (SRAM) and Dynamic Random Access Memory (DRAM) functions are provided on separate integrated circuits, and an interface protocol for transmitting information between these two memory components are provided to improve performance of the system, as well as reduce pin count and cost. An integrated circuit memory includes a random-access memory. The random-access memory includes a first terminal for receiving selection information. The random-access memory includes a second terminal for selectively (i) receiving a command, or (ii) receiving or transmitting data in accordance with the selection information received by the first terminal.

Abstract: Active control feedback between a base station and user equipment in a wireless communications network is achieved by allocating a first time slot within a frame for a UE to transmit a beacon signal to the base station, where the beacon signal is separate from data signals in the frame, allocating a second time slot within the frame for the base station to transmit a control signal in response to the beacon signal, and allocating other timeslots for the base station to operate in full duplex FDD mode. The control signal provides a basis upon which the UE adjusts a transmission parameter, such as power.

Abstract: An apparatus and method of aiding synchronization between a master transceiver and a slave transceiver is disclosed. The method includes the master transceiver transmitting data signals that are received by the slave transceiver. The slave transceiver locks a slave clock to the data signals with a slave phase-locked loop. The slave transceiver transmits slave clock information to the master transceiver.

Abstract: A transition signal generator is used to for controlling a booster of a time division duplex signal in a communications system. The transition signal generator includes a signal sampler for sampling the time division duplex signal, a power detector for detecting a power of the sampled signal, and a timing control unit for generating a logic signal indicating a direction of the sampled signal from the detected power of the sampled signal.

Abstract: A station grouping mechanism has been presented for a wireless device that collects Multi-hop Relay Base Station (MR-BS) and Relay Stations (RSs) into groups according to their locations in a tree topology and assigns them with a phase. Grouping or partitioning MR-BS and RSs and assigning a distinct phase to the group prevent the MR-BS and the RSs from transmitting and receiving at the same time.

Abstract: Training sequence interference in an equalizer-based receiver in a time-division duplex (TDD) communication system can be avoided without using interference cancellation, by providing to the equalizer both the desired data portion of the received signal, and a portion of the training sequence that is adjacent the desired data portion and has a length commensurate with the delay spread associated with the training sequence interference. The portion of the equalizer output that corresponds to the adjacent training sequence portion can be discarded while retaining the desired equalized data.

Abstract: An access point (108) in a dual-frequency TDD communication system (100) includes a transceiver (122) that transmits information to a first group of subscriber devices (104a-n) at a first frequency (f1) and contemporaneously receives information from a second group of a subscriber devices (106a-n) at a second frequency (f2) during at least a portion of a period of time (T1). The access point (108) also transmits information to the second group of subscriber devices (106a-n) at the second frequency (f2) and contemporaneously receives information from the first group of subscriber devices (104a-n) at the first frequency (f1) during at least a portion of a second period of time (T3). A method for performing a dual-frequency communication scheme is also provided.

Abstract: In the inventive circuit arrangement and appertaining method, data of at least respectively one ISDN data connection, a traditional telephone connection as well as of a broadband data connection are transmitted in an SDSL frame of an SDSL data connection, where the necessary control data are suitably transmitted in the overhead of the SDSL frame.

Abstract: A wireless communication network has radio resources for use to support calls over circuit switched (CS) and packet switched (PS) channels. The network uses such radio resources to first support CS calls and thereafter uses the leftover radio resources to support PS calls. The present invention provides method and apparatus that effectively schedule and support incoming CS calls based on frame-offset selection so as to maximize the leftover radio resources that could be used to support PS calls.

Abstract: Method and apparatus for allocating time slots in a time division duplex communication system. First and second types of time slots selected from receiving and transmitting type time slots are allocated as the first and second time slots, respectively, in a current frame. Based on an amount of information to be transferred, it is determined whether at least one time slot following the second time slot of the frame should be allocated as the first type of time slot, and if so, the last time slot of the frame is always allocated as the first type of time slot, whereby the last time slot of the frame and the first time slot of a succeeding frame are of the same type. If an additional time slot(s) is allocated for the second type of time slot, the third slot is always designated for the second type.