Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively.

Abstract: A device that is part of, and is addressable in, a local area network in a building for coupling a digital data signal to a data unit, the network including at least part of an existing telephone wire pair terminated by an outlet, the wire pair carrying a frequency multiplexed analog service signal and a digital data signal. The device includes: a telephone connector for connecting the device to the telephone wire pair; a filter coupled to the telephone connector to pass only the digital data signal; a modem coupled for bi-directional digital data signal communication with additional modems over the telephone wire pair; a data connector for connecting to the data unit; a data transceiver coupled to effect full-duplex serial digital data communication with the data unit; a power port; and a single enclosure housing the filter, the power supply, the modem and the data connector.

Abstract: Base stations having potentially interfering terminal stations that are geographically located on the same or similar diagonal or Line of Sight (relative to the base station) operate on a first set of time frames (e.g., “even” time frames). Similarly, base stations having potentially interfering terminal stations that are not geographically located on the same or similar diagonals operate on a second set of time frames (e.g., “odd” time frames). By alternating in their use of the even and odd frames, the potential for co-channel interference between terminal stations is minimized. Systems and methods are disclosed which reduce co-channel and adjacent channel interference between terminal stations of different cells as well as adjacent channel interference between terminal stations of adjacent cells. The methods and systems so described can be used during the deployment or expansion of a communication system in a region.

Abstract: One embodiment of the present invention provides a system that facilitates selectively increasing the operating frequency of an electronic circuit, such as a computer system. The system begins by operating in a low-power state with the frequency and voltage of the electronic circuit set to low levels. Upon recognizing the need for performance beyond the low power level, the electronic circuit enters the first-intermediate power state. In this first-intermediate power state, the frequency and voltage are set to first-intermediate levels. Upon recognizing the need for performance beyond the first-intermediate power state, the electronic circuit enters the maximum-sustainable power state. In this power state, the frequency and voltage are set to maximum sustainable levels. Upon recognizing the need for performance beyond the maximum-sustainable power state, the electronic circuit temporarily enters a boosted power state beyond the maximum-sustainable power state.

Abstract: The transmitter comprises a data/modulation control section (4) which sets predetermined parameters necessary for demodulation processing, sub-carrier group modulation processing sections (6a to 8c) which perform frequency spreading for each sub-carrier signal in the sub-carrier group, and time spreading sections (10a to 10c) which multiplex all signals after the modulation processing and the frequency spreading for each sub-carrier signal, and perform time spreading with respect to the multiplexed signals. The receiver comprises time despreading sections (35a to 35c) which perform time despreading for each sub-carrier signal, and sub-carrier group demodulation processing sections (36a to 38c) which perform frequency despreading for each sub-carrier signal after the time despreading.

Abstract: A telecommunications system comprising: a plurality of transmitters capable of transmitting data in superframes, each superframe comprising a plurality of frames, and each frame comprising a plurality of slots; the transmitters being arranged in groups, each group comprising a number of base stations, each group of base stations being assigned one or more slot numbers which are different from those of other groups and each of the transmitters of each group being assigned a different frame number, each transmitter being arranged to operate at reduced transmission power for a period commencing in the allocated slot or slots assigned to its group in the frame assigned to it.

Abstract: One of the common channels of the GSM system is the paging channel (PCH) for alerting the mobile station of an incoming call. The PCH message is scattered among four bursts as a result of coding, interleaving, and mapping processes before transmission. It is a waste of power for a handset to turn on and analyze all four bursts if the PCH message is a dummy one. Ideally, a handset needs to be able to make a determination whether a PCH message is a dummy one in as short of a time as possible and, if it is, turn off the power. Embodiments of this invention include methods and apparatus for enabling a handset to make this determination by merely analyzing the first received burst. Since most of the PCH messages are dummy ones, the proposed methods will cause noticeable savings in the power consumption of the GSM handsets.

Abstract: In a digital communication system, communication stations constitute frames to be conveyed over an interface. The frames simultaneously comprising full rate speech data and dedicated user data. A speech coder in the digital communication system generates the speech data while operating at a full rate. A user data application in the digital wireless communication system generates the dedicated user data. The system can set different service configurations supporting simultaneous transmission of speech data and dedicated user data, and can also include signaling data in the frames.

Abstract: Disclosed herein are various mechanisms for the adaptive cancellation of radio frequency interference (RFI) in Discrete Multitone (DMT)-based signal transmissions systems. various mechanisms for the adaptive cancellation of radio frequency interference (RFI) in Discrete Multitone (DMT) modulated signal transmissions systems. In at least one embodiment of the present invention, RFI introduced by one or more RFI disturbers (e.g., ham radios) into a DMT modulated signal may be detected by calculating an RFI canceller coefficient for some or all of the DMT bins of the signal, where the RFI canceller coefficient represents the correlation between the noise at the corrupted bin and the reference RFI noise. The RFI canceller coefficients for the corrupted bins may be calculated using an LMS adaptation process. Those bins where the magnitude of the corresponding RFI canceller coefficient is greater than a certain threshold may be marked as corrupted by RFI.

Abstract: A system and method to provide continuity of service in a radio broadcasting system, wherein the radio broadcasting system includes at least one modem using the COFDM technique, and transmits N time-frequency cells modulated independently of one another. A number N1 of cells conveying digital audio signal S1 and a number N2 of cells conveying analog audio signal S2 are transmitted to a receiver. When the receiver cannot decode the signal in the N1 cells, the receiver replaces the digitized audio signal S1 with the analog signal S2.

Abstract: Transmitting signals, e.g., high power narrow band signals on a periodic basis to facilitate detection of a frequency band and/or carrier signal to be used for communication with a basestation are described. The detected frequency band may be a downlink frequency band. The uplink frequency band to be used can be determined from a know frequency relationship between the detected downlink carrier and a corresponding uplink carrier or by monitoring the detected downlink frequency band for information indicating the uplink frequency band/carrier to be used. Carrier search methods involving searching for the narrowband high power signals used to provide carrier information and/or to indicate the frequency band to be monitored are described. Power detection methods can be used to detect the high power signals avoiding the need for symbol timing synchronization and/or channel estimation with regard to detection of the signals used to locate the frequency band to be used.

Abstract: A radio device having a frame structure is proposed for transmitting digital data in a radio communication system, a multiframe being used, which is made of a plurality of containers. The duration of the multiframe can be selected in such a manner that, during this time, a data packet can be filled with voice data of a predetermined bit rate. A container can be selected to be large enough, that a complete transmission frame can be accommodated therein.

Abstract: Physical channels of a new user service are to be assigned to a set of time slots in a hybrid time division multiple access/code division multiple access wireless communication system. The new user service physical channels are ordered based on a desired reception quality of each of the new user service physical channels. The new user service physical channels are assigned to the set of time slots based on the order and the time slot sequence.

Abstract: An apparatus and method having a de-interleaving memory and a controller is used for de-interleaving interleaved data in a coded orthogonal frequency division multiplexing receiver. The controller generates the correct access addresses of the de-interleaving memory for the data to be de-interleaved, and controls the read and write operations to the de-interleaving memory. The controller comprises an address generator having a plurality of base address generators, and a read/write control circuitry. By using the de-interleaving memory combined with memory address computation for the interleaved data, frequency de-interleaving, block de-interleaving and time de-interleaving are performed in one-stage approach in the COFDM receiver. The memory size is reduced and the circuitry complexity for performing the de-interleaving process is relatively low.

Abstract: Two related voiceband compression techniques are employed in order to enable an RF telecommunications base station to accommodate data signals of high speed voiceband modems and FAX machines. A High Speed Codec enables the base station to pass voiceband modem and FAX transmissions at up to 9.6 kb/s. An Ultra-High Speed Codec supports voiceband modem and FAX transmissions up to 14.4 kb/s. The High Speed Codec operates using three 16-phase RF slots or four 8-phase RF slots, and the Ultra-High Speed Codec operates using four 16-phase RF slots. Because these codecs transmit information over several RF slots which can be contiguous, the slots within RF communication channels are dynamically allocated. The Dynamic Time slot/Bandwidth Allocation feature detects and monitors the data transmission and forms a data channel from the necessary number of slots.

Abstract: The present invention provides methods and apparatus for a wireless system broadcasting a plurality of data packets to at least one wireless terminal. The wireless system comprises a plurality of base stations that interfaces to a backbone network in order to receive the plurality of data packets from a service source. Data packets are sent to a wireless terminal by a first base station transmitting a first channel burst and by a second base station transmitting a second channel burst, in which corresponding time offsets of the channel bursts, as characterized by amounts phase shifts, are different. Consequently, when the wireless terminal executes a handover from the first base station to the second base station, a probability that some of the data packets are lost, as result of practical network considerations, is reduced.

Abstract: When wireless communications systems are operating in the same general area, collisions between their transmissions are bound to occur. The collisions reduce the performance in the networks. In some wireless communications systems that use a fixed or prespecified transmission frequency pattern, a look-ahead technique that investigates the quality of the communications channel at the upcoming transmission frequencies can be used to allow or disallow transmissions. Additionally, a maximum length of a transmission can be determined based on the quality of the transmission frequency. Finally, if the communications system is controlled by a centralized controller, moving the controller away from sources of interference will often improve performance.

Abstract: Physical channels of a user service experiencing high interference levels are to be reassigned in a hybrid time division multiple access/code division multiple access communication system. Time slots of the user service are ordered in a descending order of the measured interference. The user service physical channels in each time slot are sequentially evaluated and reassigned in the time slot order in a descending order of a desired reception quality of each physical channel of the user service.

Abstract: A method and apparatus for reserving bandwidth in a network includes a series of elements. A demand matrix is calculated, for bandwidth requirements based upon communication needs among a plurality of nodes on the network. An integer number of time slots is provided, aligned around the network. Bandwidth is reserved for node-to-node communication based upon the demand matrix. The reserving of bandwidth reserves bandwidth between two nodes based upon time-slot alignment. Transmission is scheduled between the two nodes by reservation of wavelengths and time slots.

Abstract: A device for coupling first and second bi-directional wired digital data signals to each other and to a data unit, for use with first and second service wire pairs installed at least in part in walls within a building. The first service wire pair concurrently carries the first bi-directional wired digital data signal and a first service signal carried over a first service signal frequency band, using frequency division multiplexing. The first wired digital data signal is carried over a frequency band distinct from the first service signal frequency band. The second service wire pair concurrently carries a second bi-directional wired digital data signal and a second service signal carried over a second service signal frequency band, using frequency division multiplexing. The second wired digital data signal is carried over a frequency band distinct from the second service signal frequency band.

Abstract: A wireless sensor and control system includes wireless RF transmitter units and one or more receivers that communicate using more than one narrowband radio channel to provide increased reliability in the presence of unintentional radio interference. The output of a sensor transducer or closure of a switch contact can trigger transmissions at two or more narrowband carrier frequencies that are subsequently decoded by the receiver(s). The remote sensor data can then be passed to another system for processing and/or utilized to control remote devices. In accordance with one practical embodiment, the remote sensor data indicates the ingress or egress of monitored product inventory.

Abstract: A few high power tones used for synchronization and/or other purposes are transmitted in a FDM system during a period of time, e.g., a symbol transmission time period. During normal data transmission symbol periods signals are transmitted using at least 10 tones, e.g., per symbol time. Less than 5 high power signals are transmitted in a symbol time with at least 80% the maximum total transmitter power transmitted being allocated to the high power signals where the maximum total transmitter power is determined from a period of time which may includes one or more data and/or high power tone transmission periods. When the high power tones are transmitted at most 20% of transmitter power is available for transmitting other tones with the power normally being distributed among multiple tones. Normally some tones which would be transmitted in a symbol time go unused during transmission of the high power signals.

Abstract: A system and method for allocating one or more portions of the frequency spectrum among a plurality of radio frequency (RF) transmitters and/or receivers. The system comprises a hub station that dynamically allocates the frequency spectrum in response to demand of the plurality of RF transmitters and/or receivers. Based on the demand, the hub station analyzes the state of performance of one or more groups of RF transmitters and/or receivers, and optimizes utilization of the assigned frequency spectrum.

Abstract: The invention relates to a channel entering method for a RF communication system, in particular an indoor network, comprising a plurality of subscriber stations), each of said subscriber stations having a transmitter and a receiver, whereby information can be exchanged between said subscriber stations using respective transmitters and receivers and a plurality of channels available for RF communication in said RF communication system.

Abstract: A cellular radio communication system operating in accordance with a time division multiple access protocol assigns different fractional loading factors to different time slots. As a result, as well as because of the effects of local propagation conditions, different time slots will have different interference levels. A mobile station in a worst-case propagation environment (such as near the edge of a cell or when subject to severe shadowing fading) can be assigned a time slot having a low interference level, while a mobile station in a good propagation environment can be assigned a time slot having a higher interference level.

Abstract: A system for providing statistical multiplexing of speech, other real-time data services and non-real-time data services for point to point and point to multipoint communications. The system has fast access and assignment procedures that allow the multiplexing of real-time, delay-critical data services with non-real-time data services. Continuity of periodic control channels across speech talkspurt and silence periods for conversational voice is maintained to carry signal measurement reports, channel quality feedback, and “comfort” noise information between different parts of the system.

Abstract: A method and system begin at a random node of a trellis model having a set of at least two axes, wherein one axis corresponds to time and a second axis corresponds to frequency, a set of M states, corresponding to a set of all possible frequencies that may be transmitted by the system, and branches leaving each state, that terminate at allowable transmit frequencies for a next frequency hop. The number of branches leaving each state is dependent on the number of encoded bits per hop. Next, B bits of data are passed to a buffer, where B is the number of bits that will be transmitted per frequency hop. The method and system then combine the B bits of data with information for previously selected frequencies to select a current frequency, transmit the selected frequency, and feedback the currently selected frequency information to be used as previously selected frequency information when selecting a next frequency.

Abstract: A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory.

Abstract: An asymmetrical network for coupling customer-premises Internet hosts such as personal computers to the Internet. The head end of a CATV system has a high-bandwidth connection to the Internet. The down link connecting the personal computers to the Internet is the cables provided by the CATV system; the up link is a telephone connection to the head end. A router is connected to the down link by means of a RF modem, to the up link by means of an analog modem, and to a LAN which is connected to the Pcs. The router routes IP packets for the hosts that are received on the CATV cable to the hosts via the LAN; it routes IP packets from the hosts that are destined for the Internet to the head end via the telephone line. The asymmetrical network conserves IP addresses and addresses on the CATV cable by dynamically allocating the IP addresses for an RF modem's hosts and an address on the CATV cable for the RF modem in response to a request made by the RF modem via the telephone line.

Abstract: Systems and methods for sharing a single decoder among data streams originating with multiple sources. Error correction coding techniques are modified to facilitate decoding of data from multiple sources multiplexed in the time domain at the decoder input. A single decoder accommodates multiple sources that have been encoded using disparate code rates. One application is an OFDM point to multipoint system.

Abstract: A wireless communication network includes a plurality of mobile nodes each including a transceiver, a phased array antenna connected to the transceiver, and a controller connected to the transceiver. The controller schedules a respective semi-permanent time slot for each time frame to establish a communication link with each neighboring mobile node and leaves at least one available time slot in each time frame. The controller also schedules the at least one available time slot to also serve the communication link with a neighboring mobile node based upon link communications demand. The phased array antenna is aimed by the controller towards each neighboring mobile node during communication therewith. The controller also detects interference in time slots for communication with neighboring mobile nodes and coordinates the scheduling of time slots based upon detected interference.

Abstract: A system and method for providing a local area network utilizing discrete multitone transceivers includes at least two discrete multitone transceivers each of which may be capable of communicating with the central office and with other discrete multitone transceivers in communication with the local area network. The local area network utilizes a set of carriers coordinated between the first discrete multitone transceiver and the second discrete multitone transceiver providing a communication link between the first discrete multitone transceiver and the second discrete multitone transceiver.

Abstract: Physical layer structures and related access schemes for unsynchronized communication networks are provided. Access channel information, preferably including a common synchronization code associated with all transceiver stations in a communication network and a cell-specific synchronization code uniquely associated with one of the transceiver stations, is modulated onto at least one set of time-continuous signal components of a communication signal. In order to access the communication network, communication terminals search for the access channel information in one or more sets of time-continuous signal components and synchronization parameters are then determined based on a location of the access channel information in the sets of time-continuous signal components. Some embodiments of the invention provide for joint frame synchronization and coarse timing synchronization.

Abstract: A method for estimating a transmission channel from a multicarrier signal transmitted through said transmission channel, comprising real pilot symbols and so-called pure imaginary pilot symbols, consists in selecting one or several values zk of the received signal corresponding respectively to one or several real pilot symbols, and one or several values zl of the received signal corresponding respectively to one or several pure imaginary pilot symbols. The pilot symbols are sufficiently close both in frequency and in time such that it can be assumed that the fading of the signal through the transmission channel has a complex value &agr; substantially identical for the symbols. An estimated value {circumflex over (&agr;)} of &agr; for the pilot symbols concerned is then determined by minimizing a least square equation involving the values zk and the values zl.

Abstract: A receiver is equipped with a demodulation circuit for taking a signal indicating broadcast contents of an analog broadcast out of the first and second intermediate-frequency signals, and for taking a signal indicating broadcast contents of a digital broadcast out of the first and second intermediate-frequency signals. Frequencies of local oscillation signals are made to be a first frequency within a frequency band of the digital broadcast adjacent to a frequency band of the analog broadcast received by the receiver at a time of receiving the analog broadcast, and the frequencies of the local oscillation signals are made to be a second frequency equal to the carrier frequency of the analog broadcast adjacent to the frequency band of the digital broadcast received by the receiver at a time of receiving the digital broadcast.

Abstract: The invention relates to a method for connection establishment and a radio system relaying packet traffic. A terminal informs the system that it wishes to transmit data. The network part receives the message and allocates default radio resources and informs the allocated resources to the terminal. The terminal sends a first control message to inform the terminal's radio path characteristics. According to the solution of the invention, when allocating the default amount of radio resources to the terminal, the network part is arranged to reserve one or more radio blocks for the terminal's control messages. When the terminal sends the network part information about its radio path characteristics, it is arranged to inform in the message if there are additional characteristics. In that case, the terminal sends a second control message comprising information about its radio path characteristics.

Abstract: An out-of-band ranging technique is automatically initiated at a customer premises equipment unit when the equipment is installed, when power is restored after a power failure or interruption, upon verification of the equipment, upon reconnection after a disconnection of the equipment or the like. To this end, an out-of-band tone is employed that is automatically transmitted when the customer premises equipment that transmits the TDMA signal is powered ON, or transmitted in response to a specific command generated locally or remotely. Specifically, when ranging is being effected the customer premises equipment generates and transmits the out-of-band ranging tone until a message is received from a remote terminal indicating that the transmission of the ranging tone be terminated. The loop delay being determined is the delay interval between transmission of the termination message and detection that transmission of the ranging tone has terminated.

Abstract: A modem, communications system and method are provided with a transmitter and a receiver connected to a modem termination system (CMTS) by a medium. The modem has a memory forming a transmit queue including voice and video. The modem has a controller for sending data units from the receive queue to CMTS. The modem requests unsolicited grant service (UGS) from CMTS when the frame controller detects periodic stream to transmit. Upon detecting a data accumulation in the receive queue, the controller asserts a queue indicator. The Modem receives an occasional extra grant per interval and uses these grants until the queue indicator is not asserted. According to another feature, during transmission, the modem requests subsequent grants in a subsequent interval using an extended header having multiple bits for requesting the multiple grants. The CMTS allocates at least an extra grant to form a grant burst in response to the request.

Abstract: A dual-band receiver for a wireless communication device having multi-slot capability. A first oscillator generates a relatively high frequency traffic LO signal. A second oscillator generates a first relatively low frequency signal, and a third oscillator generates a fixed low frequency signal. A first mixer mixes the first and fixed low frequency signals to produce a relatively high frequency monitor LO signal. A switch selects the traffic LO signal when the receiver is in a traffic slot and the monitor LO signal when the receiver is in a monitor slot. The selected LO signal is provided to a second mixer along with the received signal to produce a first IF signal. A third mixer mixes the first IF signal and the fixed frequency signal to produce an output signal.

Abstract: Transceiver training is optimized for xDSL modems operating in TCM-ISDN environments under NEXT and FEXT interference. Current ITU-T draft recommendations provide for dual bitmaps that are switched synchronized with the burst cycle of TCM-ISDN to provide a data stream having dual bit rates. These recommendations also provide for a single bitmap mode where the NEXT bit map is off. Prior to transceiver training, a modem does not know which mode has been selected. Transceiver training is optimized if the mode selection is known prior to transceiver training and the training signals are designed properly for the selected mode. To accomplish this, the mode selection is exchanged early in the modem initialization process, for example, during initial handshaking. By exchanging the mode selection earlier in the modem initialization process, the modem is able to improve transceiver training and configure properly for the type of data communication (e.g., full-duplex, half-duplex).

Abstract: A wireless communication network includes a plurality of mobile nodes each including a transceiver, a phased array antenna connected to the transceiver, and a controller connected to the transceiver. The controller schedules a respective semi-permanent time slot for each time frame to establish a communication link with each neighboring mobile node and leaves at least one available time slot in each time frame. The controller also schedules the at least one available time slot to also serve the communication link with a neighboring mobile node based upon link communications demand. The controller waits a time period to resend another request upon simultaneously sending a request to an other mobile node and receiving a request from the other mobile node without receiving a corresponding reply.

Abstract: A bidirectional telephone communication system for supporting a multiplicity of subscriber lines between a downstream distribution terminal using only two of a multiplicity of pre-existing transmission line pairs connected between an upstream distribution terminal and a downstream distribution terminal. Said system including automatic initializing and monitoring circuitry for powering up a communication link and reestablishing the link if lost.

Abstract: In one embodiment, the present invention comprises broadcasting a broadcast burst in a broadcast channel from a base station. The broadcast channel has at least one assigned frequency and a plurality of time slots, at least one time slot being assigned for the broadcast burst. The invention further comprises transmitting traffic in a traffic channel from the base station. The traffic channel has a timed frequency hopping scheme, the hopped frequencies including the at least one broadcast channel frequency so that the traffic channel collides with the broadcast burst time slot. The invention further comprises broadcasting the broadcast burst in the traffic channel from the base station when the traffic channel collides with the broadcast channel, receiving a request for retransmission of traffic after the broadcast burst is broadcasted in the traffic channel due to a collision, and retransmitting the traffic in the traffic channel in response to the retransmission request.

Abstract: A subscriber unit synchronizes to a control channel. An assigned frequency and time slot is transmitted on the control channel to the subscriber unit. The subscriber unit is moved from the control channel to the assigned frequency and time slot. Voice information is received at the subscriber unit. The voice information is digitized and compressed to a lower bit rate. The voice information is transmitted together with an associated control channel from the subscriber unit.

Abstract: The invention reduces the circuit scale of a decoding apparatus for decoding input signals of multiple channels. A code string inputted to a code string resolver is resolved into signal components which are applied to signal component decoders for corresponding channels. The signal components decoded by the signal component decoders are applied to an adder and then added together. The added signal component is subjected to an inverse spectrum transform by an inverse spectrum transformer and then outputted.

Abstract: An FM transmitter forms a Digital Audio Broadcasting (DAB) signal comprising a digital FM signal and an analog FM signal. The FM transmitter comprises an RF nonlinear amplifier coupled to a first antenna and an RF linear amplifier coupled to a second antenna. The RF non-linear amplifier and antenna transmit the analog FM signal. The RF linear amplifier and antenna transmit the digital FM signal. The FM transmitter controls the signal transmissions such that the transmitted analog FM signal and the transmitted digital FM signal are combined, or multiplexed, together in the channel itself (here, the atmosphere) to form the DAB signal.

Abstract: A signal transmission apparatus for minimizing a PAPR in an OFDM communication system. A subband divider divides L information data subcarrier signals into M subband signals. An additional information inserter inserts into the L information data subcarrier signals P additional information subcarrier signals having a sign bit indicating insertion of a dummy sequence and an address bit indicating a position of a dummy sequence-inserted subband. A dummy sequence inserter inserts the dummy sequence into a subband in the position. An IFFT block initially generates a first OFDM symbol signal by IFFT-transforming the P additional information subcarrier signals and M dummy sequence-free subband signals, and thereafter generates a second OFDM symbol signal by IFFT-transforming the P additional information subcarrier signals and M dummy sequence-inserted subband signals.

Abstract: Method and apparatus for processing time division multiplexed (TDM) signals which may be custom in format. The TDM signal is translated to an intermediate frequency, or externally demodulated, input, and processed. Individual channels of either analog, digital or both are output. Since the configuration of the processor is software controlled, different TDM signals may be processed without reconfiguring hardware.

Abstract: A distributed system that provides performance monitoring capability across multiple nodes of a distributed application. A distributed system according to the present techniques includes a set of nodes that communicate via a network. A distributed application is performed by a set of cooperating node applications executing in the nodes. The distributed system implements techniques for generating time-stamp records for each of a set of significant events associated with one or more of the node applications. The time-stamp records provides a synchronized time base across the nodes for the significant events thereby enabling temporal ordering of the significant events.

Abstract: In the digital multi-subscriber radio telecommunication system which operates using frequency hopping technology and is intended for use in the 2.4 GHz ISM (Industrial Scientific and Medical) frequency band, in which a 20 dB channel bandwidth of a maximum of 1 MHz is prescribed, the known, DECT radio system operating using TDMA/FDMA technology is matched, in RF terms, to the ISM band and is modified such that the data transfer rate is reduced, preferably halved, by comparison with the data transfer rate of 1152 kbit/s, which is prescribed as standard for DECT. The system according to the invention can be used in cordless telephones.