612results about "Synchronisation error correction" patented technology

Methods, apparatus and systems for dynamically controlling a digital communication system, such as a DSL system, collect information about digital communication lines in the system and adaptively and / or dynamically determine line and signal characteristics of the digital communication lines, including interference effects. Based on the determined characteristics and the desired performance parameters, operation of the digital communication lines is adjusted to improve or otherwise control the performance of the system. The collection and processing of information may be performed by a party that is not a user in the system. This independent party also may control operational characteristics and parameters of the system. The invention can be used to eliminate or reduce signal interference such as crosstalk that can be induced on communication lines in systems such as DSL systems. Specific iterative power allocation and vectored transmission techniques and apparatus are disclosed.

The present invention proposes a method processing in random access procedure, comprising the following steps: when a Preamble transmitted by a random access node is detected by a base station, the base station calculating TA according to the Preamble detected by itself and transmitting it to the random access node; the base station receiving random access detection information reported from a transparent relay station and selecting a service node for the random access node; the base station receiving an uplink signaling transmitted by the random access node after the random access node adjusted the uplink timing advance according to TA calculated by the base station, and notifying the random access node of the access condition through a contention resolution message according to the selected service node, and the random access node performing an access procedure based on the access condition. According to the present invention, the duration of the random access procedure can be shortened, and the service QOS can be improved, which gives the user better service experience.

A method and system that provides for execution of a first calibration sequence, such as upon initialization of a system, to establish an operation value, which utilizes an algorithm intended to be exhaustive, and executing a second calibration sequence from time to time, to measure drift in the parameter, and to update the operation value in response to the measured drift. The second calibration sequence utilizes less resources of the communication channel than does the first calibration sequence. In one embodiment, the first calibration sequence for measurement and convergence on the operation value utilizes long calibration patterns, such as codes that are greater than 30 bytes, or pseudorandom bit sequences having lengths of 2N−1 bits, where N is equal to or greater than 7, while the second calibration sequence utilizes short calibration patterns, such as fixed codes less than 16 bytes, and for example as short as 2 bytes long.

A multiple input multiple output (MIMO) calibration device (360) for calibrating a phase relationship between at least two signals present on at least two radio frequency (RF) paths coupling a wireless communication unit and the MIMO calibration device (360) is described. The MIMO calibration device (360) is operably coupleable via at least two RF paths between a wireless communication unit and an antenna arrangement (219). The calibration device (360) comprises a processing module (490) configured to: process a coupled amount of at least one first signal from a first path operably coupleable to a first polarisation of the antenna arrangement (219) to determine at least one pilot signal from said at least one first signal; process a coupled amount of at least one second signal from a second path operably coupleable to at least one second polarisation feed of antenna arrangement (219), different to the first polarisation, to determine the at least one pilot signal from said at least one second signal; and determine a first phase relationship of the same pilot signal between the at least two RF paths.

A method and system provides for execution of calibration cycles from time to time during normal operation of the communication channel. A calibration cycle includes de-coupling the normal data source from the transmitter and supplying a calibration pattern in its place. The calibration pattern is received from the communication link using the receiver on the second component. A calibrated value of a parameter of the communication channel is determined in response to the received calibration pattern. The steps involved in calibration cycles can be reordered to account for utilization patterns of the communication channel. For bidirectional links, calibration cycles are executed which include the step of storing received calibration patterns on the second component, and retransmitting such calibration patterns back to the first component for use in adjusting parameters of the channel at first component.

Disclosed are a wireless communication apparatus and a time synchronization method performed thereby.

A receiver device implements enhanced data reception with edge-based clock and data recovery such as with a flash analog-to-digital converter architecture. In an example embodiment, the device implements a first phase adjustment control loop, with for example, a bang-bang phase detector, that detects data transitions for adjusting sampling at an optimal edge time with an edge sampler by adjusting a phase of an edge clock of the sampler. This loop may further adjust sampling in received data intervals for optimal data reception by adjusting the phase of a data clock of a data sampler such a flash ADC. The device may also implement a second phase adjustment control loop with, for example, a baud-rate phase detector, that detects data intervals for further adjusting sampling at an optimal data time with the data sampler.

A receiver device implements enhanced data reception with edge-based clock and data recovery such as with a flash analog-to-digital converter architecture. In an example embodiment, the device implements a first phase adjustment control loop, with for example, a bang-bang phase detector, that detects data transitions for adjusting sampling at an optimal edge time with an edge sampler by adjusting a phase of an edge clock of the sampler. This loop may further adjust sampling in received data intervals for optimal data reception by adjusting the phase of a data clock of a data sampler such a flash ADC. The device may also implement a second phase adjustment control loop with, for example, a baud-rate phase detector, that detects data intervals for further adjusting sampling at an optimal data time with the data sampler.

A high-speed interface apparatus and method of correcting skew in the apparatus are provided. A high-speed transmitter includes a transmission D-PHY module that generates and transmits a clock signal through a clock channel, generates a deskew synchronous code and test data in response to a deskew request signal, transmits the deskew synchronous code followed by the test data through a data channel, and transmits a normal synchronous code followed by normal data through the data channel in normal mode.

In the present invention, a method for synchronizing frequency and time in a wireless communication system and an apparatus for supporting the same are disclosed. Particularly, a method for synchronizing frequency and time performed by a terminal in a wireless communication system may include receiving a specific signal including a PSS, compensating the specific signal with at least one time offset candidate, generating at least one first differentiation value, generating at least one second differentiation value, calculating a cross correlation value between the at least one first differentiation value and the at least one second differentiation value, and estimating a time offset and a frequency offset of the PSS based on a time offset candidate that corresponds to a greatest cross correlation value among at least one cross correlation value calculated for at least one time offset candidate.

A method and system provides for execution of calibration cycles from time to time during normal operation of the communication channel. A calibration cycle includes de-coupling the normal data source from the transmitter and supplying a calibration pattern in its place. The calibration pattern is received from the communication link using the receiver on the second component. A calibrated value of a parameter of the communication channel is determined in response to the received calibration pattern. The steps involved in calibration cycles can be reordered to account for utilization patterns of the communication channel. For bidirectional links, calibration cycles are executed which include the step of storing received calibration patterns on the second component, and retransmitting such calibration patterns back to the first component for use in adjusting parameters of the channel at first component.

Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.

The invention provides a communicating system and device thereof, requiring high precision time synchronization of the terminating apparatus. The transmission device uses transmission delay time of reciprocation with the terminal and time information of the transmission device to create a correction value of time information of the terminal and transmits it to the terminal. The terminal includes expected arrival time information based on the time information of the terminal and the correction value received from the transmission device in a frame transmitted to the transmission device. The transmission device compares reception time of the frame with the expected arrival time information in the frame. If they match, the time information of the terminal synchronizes with the time information of the transmission device. If they do not match, the transmission device transmits a new correction value to the terminal. The terminal transmits a frame including expected arrival time information using the new correction value to the transmission device. By repeating such process, the time ofhte terminating apparatus is synchronized with the time of the transmission device.

A method for determining an angle of arrival (AOA) of a received signal is disclosed, comprising: generating a baseband information signal by mixing a received signal with a local oscillator (LO) signal, the received signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets; obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample; determining a transmitter phase offset based on an estimated correlation between the in-phase signal samples and the quadrature signal samples; performing a plurality of phase measurements using a plurality of antennas to obtain a plurality of phase measurements; correcting the plurality of phase measurements based on the transmitter phase offset to produce a plurality of corrected phase measurement; and calculating an AOA of the received signal based on the difference between the plurality of corrected phase measurements.

The invention discloses a parallel timing synchronization method based on precise loop filtering. The method is executed according to the following steps: 1, a parallel processing timing synchronization interpolation step; 2, a parallel processing timing error detection step; 3, a parallel processing loop filtering step; and 4, a parallel processing interpolation control step. The scheme of the invention has the advantages of fast synchronization speed and good performance, and is widely applied to the fields of digital communication such as ground wireless emergency communication, satellitesand power line communication suitable for low signal-to-noise-ratio transmission.

The invention discloses a method and a device for transmitting an ultra high-speed ethernet service. The method comprises the steps of distributing an ultra high-speed ethernet service data stream into a plurality of virtual channels; wherein, the speed of the ultra high-speed ethernet service data stream is greater than 100 GB; synchronously adding the marks of the plurality of virtual channels; branching channels to map the data of the plurality of virtual channels; and combining the data of the plurality of virtual channels and transmitting. The method employs a channeled transmission mode to transmit the ultra high-speed ethernet service transparently, and the ultra high-speed ethernet service is mapped to reduce the complexity of the ultra high-speed ethernet service into a low-speed ethernet service processing level, so that the realization difficulty is reduced.

A more cost effective wander jitter filter utilizes an excursion detector that receives a timing difference between a first signal and a second signal and supplies a first adjustment amount if a magnitude of the timing difference is above a predetermined threshold and otherwise supplies a second adjustment amount of zero. A summing circuit adjusts a magnitude of the timing difference by the first or second adjustment amount. A loop filter receives the summing circuit output and controls an oscillator. The excursion detector output (first adjustment value or zero according to the magnitude of the timing difference) is low pass filtered and the low pass filtered is reintroduced into the oscillator output or the feedback loop. The excursion detector output is accumulated and used to adjust a phase of the feedback signal from the oscillator.

The invention discloses a device and method for implementing a time-triggered Ethernet end system. Based on the Ethernet technology, the time-triggered Ethernet end system capable of transmitting time-triggered data and event-triggered data is implemented by increasing the functions of time synchronization and time trigger. A special protocol processing module of the device can process managementdata more conveniently; and a transmission processing module of the device can guarantee the reliability and the robustness of a network in the data transmission process. By adopting a precise clock synchronization protocol IEEE 1588, the method provided by the invention reduces the difficulty of implementing time synchronization on hardware, and has higher time synchronization stability and synchronization accuracy.

Circuits, methods, apparatus, and systems for recovering a clock from a spread spectrum signal having a periodic modulation profile. The circuits generally include an error detector circuit configured to compare the spread spectrum signal and a recovered clock signal, and to produce a first error signal corresponding to the periodic modulation profile and a second error signal corresponding to phase differences other than the spread spectrum modulation, a record and playback unit configured to record a value to a frequency memory, said value based on the first error signal and produce a third error signal corresponding to a predicted periodic modulation based at least in part on the recorded value, and a signal generator configured to produce the recovered clock signal in response to the second and third error signals.

An information processing apparatus is provided which includes a transmission unit for transmitting a query request for querying another device for a count value held by such other device, a reception unit for receiving a return of the count value from such other device, a correction unit for performing, at a predetermined period, correction processing for synchronizing sampling frequency with such other device based on the received count value, and a reproduction unit for reproducing content in synchronization with such other device based on the sampling frequency. The correction unit corrects by taking into account a Round Trip Time between the transmission of the query request and the reception of the return and residual difference occurred at a previous correction time.

Embodiments include systems and methods for using generalized pulse amplitude modulation (PAM-X) signaling with an at-rate not-return-to-zero (NRZ) clock data recovery (CDR) system. Some implementations include dual-mode signaling for an at-rate CDR (e.g., using standard NRZ signaling at lower operating frequencies and pseudo-NRZ signaling derived from PAM-X signaling at higher operating frequencies. Embodiments derive an apparent direction of signal transition from PAM-X signaling. The direction can be used to calculate pseudo-NRZ values. For example, when the PAM-X signal transitions in an upward direction, a pseudo-current NRZ value and a pseudo-previous NRZ value of ‘−1’ and ‘+1’ can be generated, respectively. An at-rate NRZ CDR can use the pseudo-NRZ values and a derived error value to make an offset determination. The offset determination can then be used to offset a generated clock signal in the CDR system.

The present invention provides a synchronizer of a laser communication distance measurement integration system, a synchronization method of a laser communication distance measurement integration system and a high-speed receiver by using the synchronizer. The high-speed receiver receives high-speed signals, an analog-digital converter (ADC) is used for sampling of the high-speed signals, the sampling data is sent into a Gigabit transceiver (GTH) to perform serial-parallel conversion, and the high-speed serial data is converted to multi-path parallel data with low rate; the parallel data is sent into the synchronizer for signal synchronization, the parallel data is subjected to steps such as parallel data frame capture, dynamic correction, high-speed phase-locked loop tracking and the like in the synchronizer so as to complete accurate synchronization of the high-speed signals through the receiver; and moreover, on the basis of the accurate synchronization of the signals, and a distance measurement result and communication data can be solved out through the distance measurement branch and the communication branch of the receiver. The clock load is reduced and the complexity of the hardware realization is effectively reduced while ensuring the accurate synchronization of signals and accurate distance measurement and communication result.

A time synchronization system comprises a time master, a time slave, and a management node which are coupled to one another via a plurality of networks. The time master transmits to the time slave a time packet at a given timing through at least one of the plurality of networks. The time slave has a time correcting part for receiving the time packet transmitted from the time master and for correcting time based on the received time packet. The management node has: a network switching determining part for determining whether to switch the network for transmitting a time packet to another of the plurality of networks; and a network switching notifying part for notifying, in a case where it is determined that the network for transmitting the time packet is to be switched, information for identifying the switched-to network to the time slave.

The invention discloses a time domain joint synchronization method of downlinks, a receiving end and a system and belongs to the field of communication. The method includes the following steps: obtaining a to-be-analyzed sequence y from a received time domain signal; carrying out timed initial estimation after carrying out Alpha-multiple downsampling on the to-be-analyzed sequence y; carrying out frequency deviation initial estimation after carrying out frequency deviation compensation on the to-be-analyzed sequence y according to an integer-multiple frequency deviation estimation value Epsilon <^> obtained through use the timed initial estimation to obtain a decimal-multiple frequency deviation estimation value Epsilon <^> <f>; after carrying out frequency deviation compensation on the to-be-analyzed sequence y according to the integer-multiple frequency deviation estimation value Epsilon <^> and the decimal-multiple frequency deviation estimation value Epsilon <^> <f>, using a position interval estimated by an initial timing position and a main synchronization sequence to carry out timed reestimation so as to obtain an accurate timing position. The time domain joint synchronization method of the downlinks, the receiving end and the system solve a problem that the prior synchronization and frequency deviation estimation method is low in efficiency and long in consumed time and achieve an effect that the operation complexity is reduced and a timed synchronization result and a frequency deviation estimation result can be mutually combined to realize rapid synchronization is achieved.

Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.

A high sensitivity GPS receiver includes an acquisition engine and a tracking engine. The acquisition engine processes GPS satellite data at data rate that is substantially equal to twice the coarse acquisition (CA) code chip rate. This data rate advantageously enables the acquisition engine to process GPS satellite data with relatively less hardware area than traditional GPS acquisition approaches. In one embodiment, the high efficiency acquisition engine may be over-clocked, thereby allowing different phases of a CA code to be correlated quickly. The tracking engine can advantageously processes GPS satellite data at a data rate that does not have an integer relationship to the CA code chip rate.

A radio measurement apparatus comprising: an array antennal selection unit selecting array antennas corresponding to received signals; a reference path selection unit selecting a reference array antenna; a signal processing unit selecting a reference antenna channel through analysis of signal characteristics measured through two reception channels; a sequential channel multiplex unit determining sequentially inputting received signals of remaining array antennas to output the sequentially input signals to a receiver; and a correction signal input unit compensating amplitude and phase characteristics of the respective reception channels.

A method comprising generating a baseband information signal by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency; obtaining baseband signal samples of the baseband information signal having a baseband signal magnitude and a baseband signal phase; determining a cumulative phase measurement associated with baseband signal samples having a baseband signal magnitude greater than a threshold; and, applying a correction signal to compensate for an LO frequency offset of the LO frequency based on the cumulative phase.

The invention discloses a precise-point-positioning-based real-time time transfer method. According to the method, carrier phase and pseudorange data of a navigation satellite as well as a broadcasting ephemeris and a broadcasting on-board clock are measured and extracted by a measurement receiver; cycle slip detection and non-difference integer ambiguity resolution are carried out on real-time carrier phase data according to real-time ephemeris and on-board clock revised data broadcast by a network server in an IGS data center to obtain time difference between local time and satellite system time; and data exchange is carried out with a communication module after error correction is performed according to a classical precise point positioning model, thereby realizing real-time time transfer between two stations.

Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.