Abstract: A method for detecting a delimiter pattern (SOF) in a signal stream containing a carrier or subcarrier modulated by the delimiter pattern comprises: specifying an expected delimiter occurrence time (t1) of an occurrence of the delimiter pattern and a tolerance zone (tz) within which the expected delimiter occurrence time (t1) may jitter; approximating, within the tolerance zone (tz), a zero of a cross correlation function (CCF) of the data stream with the delimiter pattern, or detecting the phase (?) of the carrier or subcarrier in respect to an arbitrarily defined reference position within the tolerance zone (tz), e.g.

Abstract: A receiver in an impulse wireless communication. The receiver (300) includes a pulse-pair correlator (304) that receives a signal (316) and divides it into two signals for paths. One of the signals is input to signal multiplier (312) while another signal is delayed by a delay unit (310). The signal multiplier (312) multiplies the received signal (316) by a delayed signal (318). An integrator (314) integrates an output signal (322) over a designated period of time. An adding module (306) sums an output signal (324) from the integrator (314). An acquiring module (308) compares an summing-up output (326) from the adding module (306) with a predetermined threshold value to detect the existence of a transmitting-standard preamble.

Abstract: Clear channel assessment (CCA) is a very important issue in Ultra-Wideband (UWB) systems. An effective CCA mechanism will have a large impact on the overall throughput of the communications system. It is disclosed methods and circuits to carry out CCA determinations exploiting the structure of the pulse signal either by using a moving average or by performing a cross-correlation with a locally generated signal.

Abstract: A system includes an input, a differential demodulation module, a magnitude measuring module, a summing module, and a metric generator module. The input receives input signals that include s sets of modulated sub-carriers carrying symbols, where s is an integer greater than or equal to 1. The differential demodulation module generates differentially demodulated signals based on the input signals. The magnitude measuring module measures magnitudes of real portions of the differentially demodulated signals. The summing module generates s sums, wherein each of the s sums is a sum of the magnitudes generated based on a respective one of the s sets. The metric generator module generates metrics for the symbols based on the s sums.

Abstract: A base station including a transmitting and receiving amplifier for amplifying CDMA signals exchanged with a mobile station; a radio stage connected to the transmitting and receiving amplifier for carrying out D/A conversion of a transmitted signal that undergoes baseband spreading, followed by quadrature modulation, and for carrying out quasi-coherent detection of a received signal, followed by A/D conversion; a baseband signal processor connected with the radio stage for carrying out baseband signal processing of the transmitted signal and the received signal; a transmission interface connected with the baseband signal processor for implementing interface with external channels; and a base station controller for carrying out control such as management of radio channels and establishment and release of the radio channels. The base station communicates with the external channels by mapping logical channels into physical channels. The CDMA signals are spread using a short code and a long code.

Abstract: Signalling uplink and downlink scheduling grants for a plurality of subframes in a time division duplex frame is addressed. In one aspect the allocated uplink subframes are divided into groups, so the number of groups equals the number of downlink subframes being allocated. Uplink grants for the groups are sent with the downlink grants, and for those groups that have more than one uplink subframe, the grant message also indicates which uplink subframes are included in that group. In another aspect there are two sets of grant messages, one for the uplink subframes and one for the downlink subframes. Each of the uplink grant messages is sent on a different uplink grant message, and there is a one-to-one correspondence between the uplink grant channel and the uplink subframe being scheduled by the grant. That correspondence may also be signalled with the grant messages.

Abstract: A mobile station device transmits a random access preamble to a base station device and performs uplink timing alignment based on the synchronization timing deviation information included in a random access response which the base station device transmits in response to the transmitted random access preamble, wherein in an uplink synchronous status, the mobile station device does not perform uplink timing alignment based on synchronization timing deviation information included in a random access response, which is a response to a random access preamble whose preamble ID is randomly selected by the mobile station device.

Abstract: A method and telecommunications node for implementing Tandem-Free Operation (TFO) between a pair of TFO partners in a telecommunications network. At call setup, a TFO negotiation is performed between the partners. Thereafter, if TFO is interrupted in at least one direction, state information and synchronization of the sending and/or receiving partner is maintained in the interrupted direction. An interruption may occur, for example, if a tone or announcement is to be sent. At the end of the interruption, sending and receiving of TFO frames is resumed with the same phase that was present before the interruption.

Abstract: A method for detecting a specific timing from a synchronization channel is described. A signal with a known sequence is received. Two or more correlation values between the received signal and the known sequence are calculated at two or more positions. The two or more correlation values are compared. A determination is made whether the position of the known sequence has been shifted based on the comparison. A specific timing of a synchronization channel is detected based on the determination.

Abstract: Producing coherent symbols from a plurality of digital RF transmitters is achieved by selecting data bytes corresponding to mobile-handheld encapsulation (MHE) packets and setting trellis coders to a predetermined state when a predetermined number of bits of the data bytes enter a corresponding trellis coder.

Abstract: In a wireless 802.15.4 communication system, a method and system are provided for switching between a predetermined protocol transmission mode and a high-speed transmission mode by including signaling mode information in a data packet (330, 340) to instruct the receiver device (300) to demodulate at least a data payload using the predetermined transmission mode if the signaling mode information comprises a first predetermined value, and to demodulate at least the data payload using the high-speed transmission mode if the signaling mode information comprises a second predetermined value. The signaling mode information may be included in the SFD field of an 802.15.4 SHR structure to instruct the receiver how to demodulate or process the data packet, or may be included as desired anywhere in the data packet to instruct the receiver how to demodulate or process one or more subsequent data packets.

Abstract: The present invention relates to a frame transmission scheduling method of a wireless communication considering frame transmission delay time information. The present invention provides a wireless communication system, which comprises a transmitting station for storing a transmission time in a transmission frame, calculating a delay time using the transmission time when retransmission of the transmission frame is requested, and scheduling the transmission of the transmission frame using the delay time; and a receiving station for transmitting a response frame (ACK frame) to the transmitting station when receiving the transmission frame. According to the present invention so configured, since transmission delay time information of a frame is considered when scheduling a sequence of frame transmission, there is an advantage in that waste of wireless resources due to retransmission delay of frames can be prevented.

Abstract: The present technology relates to protocols relative to utility meters associated with an open operational framework. More particularly, the present subject matter relates to protocol subject matter for advanced metering infrastructure, adaptable to various international standards, while economically supporting a 2-way mesh network solution in a wireless environment, such as for operating in a residential electricity meter field. The present subject matter supports meters within an ANSI standard C12.22/C12.19 system while economically supporting a 2-way mesh network solution in a wireless environment, such as for operating in a residential electricity meter field, all to permit cell-based adaptive insertion of C12.22 meters within an open framework. Particular present features relate to operation at the node level of a Discovery Phase in a frequency hopping network.

Abstract: Disclosed herein are techniques, systems, and methods relating maintaining a time base between receiving and transmitting assemblies during interruption of data streams communicated therebetween.

Abstract: In a wireless 802.15.4 communication system (300), a high-speed data frame structure (340) is provided which uses the 802.15.4 SHR structure that is spread modulated to obtain the synchronization benefits of the 802.15.4 protocol, but which uses a modified data frame structure for the payload portion without using spreading to thereby improve its transmission efficiency. The transmission efficiency can be further increased by increasing the size of the data payload (and correspondingly, the frame length size).

Abstract: A method for scanning a TDMA channel by a mobile station in a wireless communications landscape is disclosed. A mobile station detects RF energy on a TDMA channel to detect activity in the detected RF energy. The mobile station maintains knowledge of previous activity on the channel. If activity is present on the channel, the mobile station performs inspection of the activity to determine whether the activity is activity of interest, wherein the activity is activity of interest based on a comparison of the activity with the previous activity. The mobile station aborts the inspection of the activity, if activity is not present on the channel and the mobile station aborts the inspection of the activity, if the determined activity is not activity of interest.

Abstract: A data transmission circuit that converts parallel data signals into a serial data signal to transmit the serial data signal includes a clock generation circuit, an output circuit, and a shift register circuit for securely conducting data communication among internal elements regardless of the improvement in data transfer rate, the increase in manufacturing variance, the variation in power supply voltage and temperature, and the like. The clock generation circuit generates a clock signal. The output circuit is provided to output the serial data signal. The shift register circuit acquires the parallel data signals and sequentially transfers the acquired parallel data signals to the output circuit in a bitwise manner with the use of a shift operation synchronized with the clock signal from the clock generation circuit.

Abstract: A digital broadcast transmitting/receiving system and a method for processing data are disclosed. The method for processing data may enhance the receiving performance of the receiving system by performing additional coding and multiplexing processes on the traffic information data and transmitting the processed data. Thus, robustness is provided to the traffic information data, thereby enabling the data to respond strongly against the channel environment which is always under constant and vast change.

Abstract: Provided are an apparatus and method for deciding a transmission format using a variable frame length and a decoding method using the same. The apparatus for deciding the transmission format using the variable frame length includes: a frame synchronization acquiring unit for acquiring a frame synchronization of a received transmission frame; a correlation analyzing unit for performing a correlation analysis with respect to the transmission frame whose synchronization is acquired, considering frame lengths of respective frame structures; and a transmission frame structure deciding unit for deciding the structure of the received transmission frame using the analyzed correlation. Accordingly, a physical layer signaling code (PLSC) demodulation and decoding performance can be enhanced by determining the structure of the transmitted frame without carrying out a PLSC decoding in such a state that a frequency synchronization is not acquired.

Abstract: A communication system includes a plurality of mobile nodes forming a mobile ad-hoc network (MANET) and having a network clock time. A plurality of wireless communications links connects the mobile nodes together. Each mobile node includes a communications device and controller for transmitting and routing data packets wirelessly to other mobile nodes via the wireless communications link using a Time Division Multiple Access (TDMA) data transmission. Each mobile node includes a clock circuit having a digital clock time. A clock circuit is operative for processing a second order internal clock compensation factor as a learned and accumulated value for establishing a virtual clock time to correct any clock timing errors of the physical clock time from the network clock time.

Abstract: A router is provided including a line card (LC), an active master board (AMB), a standby master board (SMB) and a LC for implementing a simple synchronization of a link state database (LSDB).

Abstract: In a cellular system in which OFDM is used, a forward link synchronization channel, a common pilot channel structure, an initial cell searching method of a mobile station, and an adjacent cell searching method for handover are required. A method of transmitting a forward synchronization signal in a wireless communication system according to the present invention includes generating a frame comprised of a plurality of sync blocks; and transmitting the frame through a forward link, wherein the frame comprises primary synchronization channel sequences which provide timing information of the sync blocks and a plurality of secondary synchronization channel sequences which provide timing information of the frame, wherein a cell identifier is specified by a combination of the primary synchronization channel sequence and a hopping code word specified by the plurality of the secondary synchronization channel sequences. Therefore, the cell searching time can be efficiently reduced in an OFDM system.

Abstract: Timing parameters and an identity of a particular one of a number of cell groups are indicated in a signal transmitted in a cellular communication system having a radio frame in a physical layer, the radio frame comprising a number of time slots. In a known one of the time slots, a synchronization signal, S1, is transmitted that comprises a pair of sequences arranged in a first ordering. In another known one of the time slots, a synchronization signal, S2, is transmitted that comprises a pair of sequences arranged in a second ordering. The selected pair of sequences is uniquely identified with the particular cell group, and the first ordering of the sequences is used only for transmission in the known one of the time slots, and the second ordering of the sequences is used only for transmission in said another known one of the time slots.

Abstract: A variable code-tracking loop filter in a receiver having the ability to change its parameters multiple times in response to received signals. Parameters for the code-tracking loop filter may be varied based on phase and frequency errors from an error detector. In one implementation, the code-tracking loop filter is able to repeatedly vary a single parameter, such as its received bandwidth, based on the phase and frequency errors, while in another, the code-tracking loop filter may vary two or more parameters, such as the loop bandwidth and the natural frequency.

Abstract: A wireless local area network (WLAN) transceiving integrated circuit services voice communications in a WLAN with at least one other WLAN device. The WLAN transceiving integrated circuit includes a WLAN interface, an input buffer, a transcoder, and a processor. The WLAN interface wirelessly communicates with the at least one WLAN device to receive packetized audio data from the at least one WLAN device. The input buffer operably couples to the WLAN interface and receives the packetized audio data from the WLAN interface. The transcoder converts the packetized audio data to Pulse Code Modulated (PCM) audio data and outputs the PCM audio data to a coupled audio COder/DECoder (CODEC) such that the PCM audio data is substantially temporally aligned with Radio Frequency (RF) slots of the WLAN interface.

Abstract: A source communication device includes a source network clock to control timing of communicating with other devices in a network, a source streaming clock associated with processing of audio or video data, a time stamp generator to generate a time stamp that includes a source network clock value and a source streaming clock value, and a time stamp insertion mechanism that incorporates the time stamp into a data unit that is to be transmitted to one of the other devices in the network. A sink communication device includes a sink network clock synchronized with the source network clock, a sink streaming clock associated with processing of audio or video data, and a sink time stamp mechanism to compare a sink streaming clock value with the source streaming clock value, and adjust the sink streaming clock based on the comparison.

Abstract: A WLAN compliant device which comprises a VCX), a MAC, a decoder which outputs video wherein said device compares time stamps to obtain a difference.

Abstract: Methods of searching for a sync word in an MPEG compressed audio bitstream including a plurality of MPEG audio frames can include determining whether first data in the bitstream has a value equal to a sync word value. It can be determined whether the first data is a valid sync word based on a comparison of a plurality of data that are separated in the bitstream from the first data by at least a frame length to the sync word value.

Abstract: In the communication system performing transmission with generating the vacant period in the slotted mode during data transmission in order to perform various process, such as different frequency carrier quality measurement or so forth, the control signal for maintaining a communication quality is inserted even in the vacant period. Therefore, a link quality may not be degraded even if the vacant period is long. Namely, when the pilot signal is used as the control signal, even in the vacant period, measurement of the link quality of the forward link with the pilot signal is performed in the mobile station to report the result of measurement to the base station. Therefore, transmission power control of the forward link can be performed according to the report in the base station. Therefore, degradation of the forward link can be eliminated.

Abstract: A system, method and computer readable medium for mediating communication between a mobile device and a data source over a network is described. The system includes an asynchronous message receiver that is configured to receive an asynchronous request message from the device. The asynchronous request message includes an identifier field for identifying the asynchronous request message and a message field. The system also includes a synchronous message transceiver communicatively coupled to the asynchronous message receiver and configured to synchronously communicate with the data source by sending a synchronous request message to the data source and receiving a synchronous response message from the data source in return. The synchronous request message includes the message field of the asynchronous request message. A rules processor also forms part of the system, and is communicatively coupled to the synchronous message transceiver.

Abstract: A method and system for MLPPP sequence number synchronization between the active and standby side transmitters is disclosed. The MLPPP sequence number synchronization system includes a method for the standby side to associate transmit frame fragment numbers used by the active side to those generated by the transmitter on the standby side. The association is used to produce an offset which is used to synchronize the active and standby transmitters. The MLPPP sequence number synchronization system is particularly useful for overcoming the drawbacks of high bandwidth signaling between active and standby sides of switches known in the art.

Abstract: The present invention discloses a system and method for providing a secured system time reference to a subscriber device, e.g., a set top box or a receiver. In one embodiment, the system time reference is provided in a secure system time message that is broadcasted to a plurality of subscriber devices. Each subscriber device has a security device or software application that is capable of determining whether the received system time reference is legitimate. If the system time reference is determined to be legitimate, a local time reference is synchronized with said received system time reference.

Abstract: The invention relates to a method for exchanging data between stations or nodes (111, 121, 122, 123, 131, 132, 133, 141, 142, 143) from different realtime capable networks (120, 130, 140) and from non-realtime capable networks (110). To this end, data is generated in a realtime capable network (120, 130, 140), a time stamp is added, and at least two of the realtime capable networks (120, 130, 140) are synchronized with one another. The invention also relates to a method for exchanging data between stations or nodes (111, 121, 122, 123, 131, 132, 133, 141, 142, 143) from realtime capable networks (120, 130, 140) and from non-realtime capable networks (110), during which trigger signals of different stations (111, 121, 122, 123, 131, 132, 133, 141, 142, 143), particularly from different networks (110, 120, 130, 140) are combined or linked.

Abstract: Methods and systems for synchronizing wireless transmission of data packets is provided. Signals having a data packet frame format including a preamble (with a pattern of symbol sequences) and data are received, and patterns of symbol sequences are correlated. A first metric can be calculated that is a ratio of an average of the correlation values and an average of a power of the signals. A second metric can be calculated that defines an average of a power of noise in the signals. The methods include determining an approximate division of the preamble and data in the data packet of each signal based on the first and second metrics. The methods further include determining a cross-correlation between versions of a transmitted signal to produce a number of peaks equal to a number of transmit antennas, generating a third metric based on combinations of cross-correlations, and identifying a position of a maximum peak within the third metric as a fine timing offset amount.

Abstract: Systems and methods are provided that facilitate generation and detection of synchronization channels in a wireless communication system. A one-to-one relationship is established among a set of scrambling codes (SCs) and a set of primary synchronization channel (P-SCH) sequences which are determined by a reusable sector identifier that is determined through detection of the P-SCH channel. The set of scrambling codes are utilized to (i) scramble a secondary synchronization channel sequence which facilitates detection of the S-SCH sequence once the reusable sector identifier is detected, or (ii) compose an unscrambled S-SCH sequence through a sequential or interleaved concatenation of SCs wherein a concatenation indication is received in a mobile terminal. Cyclic shifts and sign-flip operations applied to a base sequence are employed to generate SCs. A lookup table and a library of SCs facilitate scrambling code determination in a mobile terminal that receives associated P-SCH and S-SCH sequences.

Abstract: To remove DC offset from received data symbols having cyclic prefixes in a data communication system, means (5) are provided for determining the location of the cyclic prefixes, means (3) are provided for calculating the DC offset by calculating a mean value of at least one data symbol without its cyclic prefix and means (4) are provided for subtracting the calculated DC offset from said at least one data symbol with its cyclic prefix.

Abstract: The present invention provides methods and systems for detecting a start symbol of a second zone of a frame. One or more symbol indices corresponding to one or more symbols of the second zone of a frame are derived. One or more codes on pilot sub-carriers corresponding to the one or more symbol indices may also be derived. Based on the one or more symbol indices a set of possible start symbol indices is established. Thereafter, a frame is received comprising one or more of a preamble symbol, a first zone and the second zone. It is determined if the received frame comprises the second zone. If the second zone is present in the received frame, the start symbol index of the second zone of the received frame is determined based on the detection of one or more codes and the set of possible start symbol indices. The present invention further provides methods and systems for detecting a Nth symbol of a frame.

Abstract: A method, mobile device, network device, and software product are for forming a time division duplex frame structure, including a downlink pilot timeslot within an initial data timeslot of the frame structure, and also including an uplink pilot timeslot in a further data timeslot of the frame structure. A guard period is located between the initial data timeslot and the further data timeslot.

Abstract: A dual mode clock and data recovery (CDR) system is disclosed. A fast locking, oversampling CDR acquisition module can begin the process to quickly create a data acquisition clock signal in start up data acquisition conditions. When at least some data can be extracted from the incoming data stream, the CDR system can indicate such stability and switch to accept control from a low power CDR maintenance module. The low power CDR maintenance module can then fine tune and maintain the timing of the data acquisition signal. If the quality of the data lock under CDR maintenance module control degrades to a sufficient degree, the high power CDR acquisition module can be re-enables and re-assert control from the low power module until such time as the lock quality is again sufficient for the low power module to be used.

Abstract: An error management system and process can be used to identify an erroneous data packet in a data stream. In response to identifying the erroneous data packet, a subsequent valid data packet is located in the data stream. In one embodiment, a plurality of candidate locations of header checksum windows are searched and checked for a valid checksum. Multiple integrity checks of multiple header checksums can be used to reduce the probability of a false positive integrity check. In another embodiment, one or more information data fields can used for determining packet integrity by determining if the fields contain valid information bits.

Abstract: A packet probe for a packet network accurately generates and monitors packets within the network. The packet probe supports packet generation and packet transmission. When a packet is ready for transmission, a hardware-based time stamp unit affixes a time stamp to the packet reflecting an actual transmission time. The packet probe also supports receiving, filtering, and time stamping received packets. When a packet is received, a packet filter determines whether the received packet should be stored in memory along with a time stamp reflecting an actual reception time.

Abstract: Methods and systems are provided to generate digital coefficients for a filter. The generation of coefficients relies on a Fourier transformation of an impulse response in time domain that is zero padded, e.g., zeros are appended to an array corresponding to a sampled input signal of length M. A unit prototypical filter is generated through a frequency domain response of length NFFT=NS+M?1, wherein NS is a sampling length of the incoming signal. The unit prototypical filter is then circularly shifted in order to generate a band pass filter centered at a desired frequency. Circularly shifted filters are point-to-point added to generate a set of composite digital coefficients to filter the incoming signal. The reference frequencies for the composite filter are extracted from a message received from one or more base stations associated with one or more service providers. The composite filter typically operates on a frequency repeater.

Abstract: A wireless communication apparatus includes a sender identity evaluating portion that evaluates whether a sender of consecutively received packets is the same, and a physical layer control portion that controls a physical layer using an evaluation result if the sender identity evaluating portion evaluates that a sender of consecutively received packets is the same.

Abstract: An ad hoc method is provided for synchronizing a wireless network. The method involves broadcasting a first signal including a join message from a first node (FN). The method also involves saving a first timestamps in a memory device internal to the FN after broadcasting the first signal. The method further involves generating a signal including a join response message after receiving the first signal. The join response message is comprised of a second timestamp indicating a local time during which the first signal was received at the second node (SN). The method also includes the step of determining an initial time offset by computing a difference between the first timestamp and the second timestamp. The method further includes the steps of generating a request to send (RTS) message at the FN. The FN uses the initial time offset in conjunction with the RTS message to asynchronously communicate with the SN.

Abstract: A method and corresponding system for communicating between stations in a network is presented. The method includes providing repeated beacon transmissions from a coordinator station for coordinating transmissions among the stations; transmitting a signal from a first station and receiving the signal at a second station; and performing one or both of: generating the signal based on a local clock at the first station and time adjustment information in a beacon transmission received by the first station, and sampling the signal at sample times based on a local clock at the second station and time adjustment information in a beacon transmission received by the second station.

Abstract: The present invention concerns a transmission method in a wireless telecommunication system including at least a base station intended to communicate with terminals over bidirectional communication channels, each channel supporting frames being divided into downlink sub frames and uplink sub frames, each downlink sub frame including a number of symbols intended to be transmitted to at least two terminals, wherein the transfer of at least one supplementary symbol between the base station and at least one terminal that can receive or transmit said at least one supplementary symbol is enabled.

Abstract: A system and method for state synchronization between a base station and a mobile station in a mobile communication system. A count value indicative of a state change of the base station is received. The received current count value is compared with a previous count value previously received and stored. If the current count value is different from the previous count value, the mobile station performs a network entry procedure with the base station.

Abstract: An exemplary embodiment of a synchronization device is provided. The synchronization device includes a memory, a demultiplexer, a comparator, and a sampling rate converter. The synchronization device has a system time clock (STC) and generates an output data with a first sampling rate. The demultiplexer receives a bit stream and extracts a packetized elementary stream (PES) from the bit stream. The demultiplexer writes the PES into the memory. The comparator obtains a presentation time stamp (PTS) from the PES and compares the PTS and the STC. The sampling rate converter has a converting factor, samples the PES in the memory, and generates the output data according to the PES. The sampling rate converter changes the converting factor according to the compared result of the comparator.

Abstract: An apparatus for transmitting terrestrial digital data using a synchronous-optical-network system or a synchronous-digital-hierarchy system includes a synchronous-difference calculating unit that calculates a synchronous difference between a standard signal used in the synchronous-optical-network system or the synchronous-digital-hierarchy system and a first synchronous signal that synchronizes with a leading position included in image data of the terrestrial digital data; and a transmission processing unit that transmits the synchronous difference together with the terrestrial digital data to a destination.

Abstract: When the synchronization information, transmitted from a synchronization information output unit of a clock master side device, is detected by a synchronization information detection unit, the clock slave side device associates the synchronization information with the timestamp information at the time of detection of the synchronization information. Based on the timestamp information associated with the currently received synchronization information, the timestamp information associated with at least one synchronization information up to the synchronization information received last time and transmission period information of the synchronization information, a calculation/decision unit decides whether or not a predetermined condition is met. When the condition is met, the calculation/decision unit supplies the currently received synchronization information to a clock synchronization technique function unit.