100 results about "Syncword" patented technology

The disclosed embodiments relate to a system and method for inserting sync bytes into a video transport stream. More specifically, there is provided a method comprising determining a parsing procedure supported by a first set top box, appending a first transport packet to comply with the parsing procedure of the first set top box, and transmitting the first transport packet to the first set top box.

Method and apparatus for transporting Ethernet data packets via radio frames in a wireless metropolitan area network. A terminal includes a data packet receiver for receiving data packets for communication over a wireless link wherein not every data packet has a same length; a data packet formatting apparatus for formatting the data packets according to radio frames wherein the radio frames each have a same length and wherein the data packets are formatted into the radio frames such that boundaries for the data packets are not necessarily aligned with boundaries for the radio frames; and a wireless transceiver for communicating the radio frames over the wireless link. The packets can be Fast Ethernet packets. The terminal does not convert the Ethernet data packets into a telephony communication protocol or into an asynchronous transfer mode (ATM) protocol prior to communication of the radio frames over the wireless link. The terminal can include a data packet synchronizer for synchronizing the data packets to a clock signal associated with the radio frames. The data packets can be time-division multiplexed into the radio frames. According to another aspect, a method of transporting Ethernet data packets via radio frames includes steps of receiving Ethernet data packets wherein each data packet includes a preamble and a start-of-frame delimiter, stripping off the preamble and start-of-frame delimiter, formatting the packet data according to radio frames, including appending a synch field to the packet data, and appending a length field to the packet data.

An apparatus for enabling transmission of parallel data from a first parallel bus to a second parallel bus via a serial data channel includes a first logic element that generates a synchronization character used in a serial data transmission protocol upon detection of a parallel synchronization packet. A serializer converts data from the first logic element into a serial data stream. A de-serializer converts the serial data stream into a plurality of parallel data packets. A second logic element detects the synchronization character and converts the synchronization character into a parallel synchronization packet.

Noise is prevented when decoding an audio stream not containing syncwords or CRC bits in the elementary stream. When decoding a current frame, the private header of the next frame is analyzed and the current frame is muted if the private header of the next frame is not valid. When there is a data discontinuity caused by editing, decoding resumes from the start address of the next frame determined by the stream analyzing means.

The payloads of IP packets are checked to actually determine if a packet contains MPEG-2 video rather than using predefined streams or priority levels that are assumed to contain such information as is done in the prior art. More specifically, the “sync” bytes of the MPEG-2 stream are searched for within the IP packet payload, and when a pattern indicative of the sync bytes is found the sync bytes are identified and the packet is determined to contain MPEG-2 video. The sync byte was defined in MPEG-2 for over-the-air broadcasting in order that a television receiver be able to synchronize the MPEG-2 transport stream packets. Note that the MPEG-2 video, e.g., the MPEG-2 transport stream packets, may or may not be incorporated within real time protocol (RTP) packets before being incorporated into the IP packets.

Variable-length information-containing frames (e.g., MPDUs) are aggregated into a bitstream using frame delimiters to distinguish the frames. Aggregation and frame extraction techniques are provided that support recovery from bit errors that may be present in a frame delimiter. One class of techniques involves providing redundant length information in the frame delimiters, e.g., by using multiple copies of a length field or error correction codes usable to correct errors in the length field. The receiver can use the redundant information to detect and correct errors in the length field. Another receiver-side technique iteratively attempts to locate the end of the corresponding frame when a corrupt frame delimiter is detected. Conventional synchronization fields may be eliminated.

Provided are a forming terminal of a time slot data frame compatible with a data chain and a working method of the same. Based on correlation of data redundancy and requirements for communication quality of service, under the condition of constant radio-frequency bandwidth, the terminal can visually and clearly display the formation process of the time slot data frame through the coordination of parts. The received service data is analyzed, and an appropriate encoding, a modulation, a spread spectrum combined technology and a data encapsulation formats are selected, then the combined technical information is creatively mapped to a fine synchronization field stuffing bits for the time slot data frame, so that when the receiving terminal is in the fine synchronization, the encoding, the modulation and the spread spectrum subsequent combined technical information of the subsequent received data are obtained, which can shorten the preprocessing time of the received data, satisfy the requirement of anti-interference, confidentiality, real-time and coverage of the data chain, and further enhance the adaptability of the data chain to future complex environments and improve system throughput. The forming terminal of the time slot data frame compatible with the data chain has the advantages of being compact, reasonable and artful in structure, being simple, convenient and easy to operate, and being promising in application prospect.

A radio controller arrangement for controlling communication signal timing in a duplex radio-frequency TDMA radio includes a TDMA timer that generates a receive timing signal and a microprocessor circuit. The microprocessor circuit commands the TDMA timer to activate the radio to receive a signal and converts the signal into packets having synchronization and data fields. The TDMA timer synchronizes a beginning of a data collection operation to the synchronization field and locates the beginning of the data field based on the end of the synchronization field. The TDMA timer collects data from the data field until it detects the end of the data field. The TDMA timer then commands deactivation of the radio. The radio controller arrangement may be incorporated into a communication device or used in connection with a method for controlling communication signal timing.

The invention relates to a technology of the communication field, in particular to a two-channel synchronization method for frequency hopping communication. The invention aims at problems in the prior art, and provides a two-channel synchronization method for frequency hopping communication. According to the method, on the basis of a synchronized-head method and through smart design on synchronized-head transmission of a transmitting terminal, a short period pseudorandom sequence is selected as a frequency control code, and through design on a synchronization code pattern, the special pattern property of a frequency hopping synchronized-head is sufficiently utilized, frequency hopping synchronization is rapidly achieved, and the problems that in the prior art TOD information is needed when the synchronized-head method is utilized, a great number of synchronization frequency points are occupied, the elusiveness in communication is low, and the like, are solved. According to the invention, whether the frequency hopping synchronization is accomplished is confirmed by carrying out relevance calculation on the frequency hopping synchronized-head, so that connection is established on the transmitting and receiving terminals so as to achieve the design. The two-channel synchronization method is applicable to the field of frequency hopping communication.

The embodiment of the invention provides a data retransmission method. The data retransmission method comprises the steps of receiving broadcast data transmitted by bluetooth master equipment at a preset receiving interval; detecting whether the broadcast data transmitted by the bluetooth master equipment is correctly received or not; and when it is detected that the broadcast data transmitted bythe bluetooth master equipment is not correctly received, requesting the bluetooth master equipment to retransmit the broadcast data, and receiving the retransmitted broadcast data. The embodiment ofthe invention further provides bluetooth slave equipment and a wireless communication system. The data retransmission method has an additional function of feeding back information of incorrect reception after the bluetooth slave equipment receives the broadcast data on the basis of the existing point-to-multipoint broadcast transmission mechanism. Whether there is bluetooth slave equipment requesting data retransmission or not is judged according to a relation between the bluetooth master equipment and the feedback data by using a characteristic that multiple sets of bluetooth slave equipmentsimultaneously transmit by adopting the same synchronization word on the same channel, thereby realizing automatic retransmission, and thus improving the reliability of point-to-multipoint broadcast transmission.

Provided is a method for detecting frame sync and frame structure in a satellite broadcasting system, which acquires an estimated value for detecting frame structure and frame sync and overcomes distortion of correlation analysis values by summing differential correlation values for SOF positions in consideration of the variable frame length, and selecting a maximum value in a channel environment with low signal-to-noise ratio and high frequency error. SOF is a sync word indicating the start point of a frame. The method includes the steps of: acquiring SOF differential correlation value sequences; acquiring sums (di,t) of the correlation values normalized for SOF positions based on the number of symbols per frame by using the above-generated SOF differential correlation value sequences; and selecting a maximum value (dz,x) among the sums of correlation values, detecting z as a frame sync position, and detecting x as a frame structure index.

In RF transceivers, a method and system for using phase shift key (PSK) sync word for fine tuning frequency adjustment are provided. One aspect of the invention provides for adjusting a local oscillator frequency in a radio frequency (RF) receiver when a residual DC offset remains after a coarse frequency offset adjustment if performed. The fine adjustment may be necessary because of the synchronization required with a PSK-based modulated portion of a Bluetooth packet. A residual phase shift detected in a sync sequence portion of the Bluetooth packet may be utilized to determine a residual or fine frequency adjustment. This approach may allow an RF receiver to operate, in some instances, without the need for an equalizer. In this regard, the power consumed by the RF receiver may be minimized and / or the overall cost of the RF receiver may be reduced.

A method and apparatus for searching the synchronization signal of a next frame in encoded digital signal without the need of referring to a frame length indication signal. The encoded digital signal contains a plurality of frames, wherein each frame may have varying length and contain a synchronization signal. The method includes determining a search region, and locating the synchronization signal in the search region.

A read channel for a hard disk controller comprising: means for generating a sequence of start of write signals to individually control the start of writing of each of one or more servo sync words to a disk; and means for individually writing the one or more servo sync words to the disk.

A predetermined syncword detecting circuit includes a matched-bit-number comparing circuit, a comparing-result-change detecting circuit, a detected-result storing circuit, a total number detecting circuit, and a syncword detecting circuit. The matched-bit-number comparing circuit acquires a number of bits in a baseband signal that matches bits of the predetermined syncword and compares the number with a first threshold. The comparing-result-change detecting circuit samples the result of the matched-bit-number comparing circuit. The comparing-result-change detecting circuit detects changes in the result of the matched-bit-number comparing circuit. The detected-result storing circuit sequentially stores a result of the comparing-result-change detecting circuit. The total-number detecting circuit detects a total number of the result of the matched-bit-number comparing circuit. The result is included in an N cycle period and surpasses the first threshold. The syncword detecting circuit detects the predetermined syncword and selects an intermediate phase of the cycles as a detection phase.

Provided are a forming terminal of a time slot data frame compatible with a data chain and a working method of the same. Based on correlation of data redundancy and requirements for communication quality of service, under the condition of constant radio-frequency bandwidth, the terminal can visually and clearly display the formation process of the time slot data frame through the coordination of parts. The received service data is analyzed, and an appropriate encoding, a modulation, a spread spectrum combined technology and a data encapsulation formats are selected, then the combined technical information is creatively mapped to a fine synchronization field stuffing bits for the time slot data frame, so that when the receiving terminal is in the fine synchronization, the encoding, the modulation and the spread spectrum subsequent combined technical information of the subsequent received data are obtained, which can shorten the preprocessing time of the received data, satisfy the requirement of anti-interference, confidentiality, real-time and coverage of the data chain, and further enhance the adaptability of the data chain to future complex environments and improve system throughput. The forming terminal of the time slot data frame compatible with the data chain has the advantages of being compact, reasonable and artful in structure, being simple, convenient and easy to operate, and being promising in application prospect.

Method and computer program product are provided to encode data for recording onto media whereby modulation and linear constraints from a concatenated code or product code are imposed. A first array of unencoded user data is generated. Each row is modulation encoded to enforce a first modulation constraint; the array is transformed into a second array which is transformed into a third array having predetermined empty locations in each column interleaved with the modulated data. A C2-parity byte is computed for at least some of the empty locations of the third array and a fourth array is generated. C1-parity symbols in each row are computed, generating a fifth array. A second modulation constraint is enforced on each C1-parity symbol in each row of the fifth array, generating a sixth array. The rows of the sixth array are assembled with header and sync fields for recording onto a recording media.

A frame synchronization apparatus and method based on differential correlation in a communication system are provided. A correlation analysis is performed by using sync word in a prior search window and a posterior search window for obtaining a plurality of prior-window correlation values and a plurality of posterior-window correlation values, respectively. N maximum correlation values in the correlation values are selected, wherein indexes of the maximum correlation values are I1˜IN, and N is an integer greater than 0. The posterior-window correlation values are compared with a first threshold. If one of the posterior-window correlation values is greater than the first threshold, the index of the one is defined as J. If the index J is equal to one of the index I1˜IN, a check step is performed by using the index J for confirming that a position of the index J is a header position.

The invention provides a space link protocol blind identification method and system. The space link protocol blind identification method comprises the steps that target data in a file to be blind identified are converted into hexadecimal data; all frequent sequences within an appointed length range are found based on the hexadecimal data to constitute an initial frequent sequence set, and statistics is performed on the number of occurring times of the sequences of each appointed length; count values of the frequent sequences obtained by the statistics are compared with a plurality of set min_threshold values one by one, and the frequent sequences of which the count values are larger than the min_threshold values are stored in a middle frequent sequence set; a pattern matching method is adopted, all sequences in the middle frequent sequence set are searched for and positioned in the target data one by one, all equally-spaced frequent sequences are extracted from the middle frequent sequence set, and a target frequent sequence set is constituted; pattern matching is conducted on the target frequent sequence set obtained by excavation and space link protocol frame synchronization word sensitive information, and applied protocol types are judged.

The invention provides a data link anti-quantum computing communication method and system based on ID cryptography and a symmetric key pool. The method comprises the following steps: firstly, allocating respective identity IDs and private keys to two communication parties through an ID cryptography mechanism, calculating opposite side public keys by the two communication parties respectively by utilizing the IDs disclosed by the opposite sides, and calculating symmetric keys according to the own private keys and the opposite side public keys; when the two parties with the symmetric key communicate with each other, enabling asender and areceiver to perform frequency hopping synchronization through adoption of a synchronization header method, and appoint to select at least one part of information in the synchronization header as initial information; enabling the initial information to besubjected to root key transformation by a key pool, so that the initial information acquired by the enemy becomes useless information; and then, based on a true random number key sequence in three links of root key calculation information encryption and message authentication, direct sequence spread spectrum and frequency hopping which cannot be obtained by an enemy, achieving anti-quantum calculation of data transmission, and therefore the security of the whole data link system is greatly improved.

The invention discloses a method and device for five times of iterative decoding of superstrong forward error correction, and relates to the field of channel error correction coding and decoding in an optical communication system. The device comprises a synchronization word analytical unit, an internal frame mapping unit, an RAM storage unit, a control unit for five times of iterative decoding, a BCH (900, 860) code syndrome computing unit, a BCH (900, 860) code BM algorithm unit, a BCH (900, 860) code data buffer unit, a BCH (900, 860) code forward search and error correction unit, a BCH (500, 491) code syndrome computing unit, a BCH (500, 491) code data buffer unit, a BCH (500, 491) code forward search and error correction unit, an internal frame inverse mapping unit and a decoding performance monitoring unit. Hardware implementation resources are small in scale, and the good coding gain error correction performance is acquired through five times of iterative decoding.

A synchronized captioning system and methods for synchronized captioning of scripted live performances are disclosed. The synchronized captioning system and methods provide accurate real-time captioning to a scripted live performance by ingesting a digital script, indexing and annotating the script with time duration, speech cadence, and performance details, and creating an enhanced digital script that includes encapsulated segments. Audience caption devices are registered to receive broadcast transmission of the encrypted script by identifying the correct encapsulated segment at the correct time. Speech is captured and converted to text, with pattern matching of text and time offset calculations timely transmit of each segment. The audience caption devices can pause, backup, move forward, and display live captions, with copyright protection enabled for the performance.

The invention relates to a frame synchronous byte recognition system based on FPGA and a recognition method, wherein, the synchronous recognition method comprises the steps as follows: counting the data byte of the current data frame of TS flow and recording the position of each byte in the current data frame; judging whether the current data frame is a first frame; recording the position of the byte with the value of 0X47 in the current data frame, and labeling; recording the number of the positions of the bytes labeled as 1 in the current data frame; entering a monitoring state when the number of the position of the byte labeled as 1 is one in the current data frame, otherwise, entering a next frame. The synchronous byte recognition method of the invention is fast and reliable and easily achieved, and can improve the synchronous speed and reduce the loss of effective data and data processing time of TS flow.

A hopping spread-spectrum wireless network for IoT applications. The network includes mobile devices with unsynchronized local clocks that transmit including, in a preamble portion, a plurality of sync words, each combined with at least one instance of a sequential index. The hopping frequencies at which the sync word are transmitted are different. This arrangement helps detection and synchronization of the signals, despite the unavoidable frequency mismatches and collisions.

Various techniques for encapsulation are described. A variable length frame is encapsulated into at least one fixed length codeword. The at least one fixed length codeword comprises an integer number of bytes. A first byte of the at least one fixed length codeword is a synchronization byte.

The invention provides a TTE network clock calibration method and system. The TTE network clock calibration system comprises a coarse synchronization subsystem and a fine synchronization subsystem, the coarse synchronization subsystem comprises a synchronization word detection module, a phase synchronization detection module and a coarse synchronization delay modulation module; the fine synchronization subsystem comprises an LMS adaptive filter training module, a coefficient storage module, a drift compensation model module and a fine synchronization delay processing module. A traditional taming crystal oscillator system adopts an analog or semi-digital system and has the defects of high cost, great influence of environmental factors, difficulty in debugging, difficulty in model establishment and the like. According to the time frequency basic principle of the taming crystal oscillator technology, the full-digital taming crystal oscillator system based on the clock model construction technology is designed aiming at the defects of the traditional taming crystal oscillator technology, the system can improve the time difference measurement precision, an advanced crystal oscillator noise model is utilized, analysis and debugging are convenient, and the time difference measurement precision is improved. The tracking capability and the holding capability are better than those of a traditional method.

A predetermined syncword detecting circuit includes a matched-bit-number comparing circuit, a comparing-result-change detecting circuit, a detected-result storing circuit, a total number detecting circuit, and a syncword detecting circuit. The matched-bit-number comparing circuit acquires and compares a number of bits in a baseband signal that matches bits of the predetermined syncword with a threshold. The comparing-result-change detecting circuit samples the comparison result, and detects changes in the comparison result. The detected-result storing circuit sequentially stores a result of the comparing-result-change detecting circuit. The total-number detecting circuit detects a total number of the result of the matched-bit-number comparing circuit. The result is included in an N cycle period and surpasses the threshold. The syncword detecting circuit detects the predetermined syncword and selects an intermediate phase of the cycles as a detection phase.

The present invention relates to methods, apparatuses, and systems for relaying data involving obtaining a data stream from a data source, forwarding the obtained data stream over a network, while forwarding the obtained data stream over the network, monitoring the obtained data stream to detect a data transfer mode associated with inclusion of synchronization characters in the obtained data stream, and if the data transfer mode is detected, removing a plurality of synchronization characters from the obtained data stream to produce a bandwidth-reduced data stream and forwarding the bandwidth-reduced data stream instead of the obtained data stream over the network. Synchronization characters may comprise start bits, stop bits, and idle bits. The data transfer mode may be an asynchronous data transfer mode based on a V.14 standard. Also, the asynchronous data transfer mode may be detected by decoding a predetermined number of valid V.14 frames from the obtained data stream.

Noise is prevented when decoding an audio stream not containing syncwords or CRC bits in the elementary stream. When decoding a current frame, the private header of the next frame is analyzed and the current frame is muted if the private header of the next frame is not valid. When there is a data discontinuity caused by editing, decoding resumes from the start address of the next frame determined.