35results about "Network synchronisation" patented technology

Disclosed are methods and apparatus used in wireless communications. The methods and apparatus establish a codebook for use in sparse code multiple access (SCMA) encoded communications, in particular. The SCMA codebook is configured to set the codebook for at least one layer (i.e., a user) to include a constellation of points having a first grouping of constellation points located at first radial distance from an origin in a complex plane and a second grouping of constellation points located at a second radial distance from the origin. This codebook arrangement provides increased gains at receivers by optimizing the constellation shape to improve the distance between constellation points (i.e., SCMA codebook performance), and in particular more robust performance when encountering amplitude and phase misalignment in uplink (UL) multiple access.

Disclosed are a sequence report method and a sequence report device for reducing a signaling amount for reporting a Zadoff-Chu sequence or a GCL sequence allocated for a cell. Indexes starting at 1 are correlated to different ZC sequences and are allocated for cells so that the indexes are continuous. When such ZC sequences are reported from BS to UE, a start index indicating the start of the continuous indexes is combined with the number of allocated sequences and they are reported as allocation sequence information by a report channel. The UE and the BS share the correlation between the ZC sequences and the indexes and the UE identifies a usable sequence number according to the correlation and the allocation sequence information reported from the BS.

A code division multiple access wireless network (10) comprises a plurality of base stations (11-14) which operate asynchronously with respect to one another. A set of scrambling codes are allocated to the base stations for scrambling signals transmitted from the base stations. A node (30) of the wireless network receives (102) a first type of measurement report from wireless terminals (20), which comprises an observed time difference measurement acquired by the wireless terminal (20) for a signal received from one of an active set of base stations (11, 12, 13) that currently serve the wireless terminal. A timing reference is determined (103) for each of the base stations using a plurality of the observed time difference measurements. A second type of measurement report is received (105) from a wireless terminal (20) which comprises an observed time difference measurement acquired by the wireless terminal for a signal received from a base station (14) which is not currently serving the wireless terminal and a scrambling code of the received signal. An identity of the base station (14) in the second type of measurement report is determined by using the scrambling code of the signal received from the base station (14) which is not currently serving the wireless terminal and the observed time difference measurement in the second type of measurement report and the determined timing reference for that base station.

The invention discloses an anti-interference high-precision signal synchronization method based on an access code in a Bluetooth receiver. The method comprises the following steps: taking the access code agreed by two parties as a local training sequence; sampling received signals, and continuously performing delay differential operation on the two sampling values at an interval of one code element period, obtaining a to-be-correlated sequence according to a result of the delay differential operation, performing sliding correlation operation on the to-be-correlated sequence and a local training sequence, searching a peak value of a correlation value, and taking a sampling moment corresponding to the peak value as an initial position of an access code, thereby realizing frame timing synchronization. According to the invention, signal synchronization is carried out by using the Bluetooth access code, interference of other signals in the same frequency band is not liable to occur, the signal detection accuracy is high, and the problem of missing detection or false detection is greatly reduced, so that the working efficiency of the Bluetooth receiver is improved, the Bluetooth communication accuracy and safety are ensured, and the communication system is more stable and reliable.

An apparatus is provided for a device-to-device, D2D, communication enabled user equipment, UE, comprising a processing section to determine, based on a signal received from another UE, a channel condition between the UE and the another UE; the UE to report the determined channel condition to an evolved Node B, eNB. The processing section is to initiate D2D communication based on a communication from the eNB, received in response to the report. Also, an apparatus is provided for a network element, comprising An input to receive a describing a channel condition between a first UE and a second UE; a processor to determine, based on the channel condition, whether or not D2D communication between the first UE and the second UE is to be enabled; and an output to output a result of the determination when the processor determines D2D communication is to be enabled. Related methods are also provided.

Data is accessed from a network via a wireless communication link. A determination is made as to whether payload data has been received from a subscriber's terminal. If so, then a request is sent for a first set of traffic channels, and the payload data is transmitted over the first set of traffic channels.

Disclosed are methods and apparatus used in wireless communications. The methods and apparatus establish a codebook for use in sparse code multiple access (SCMA) encoded communications, in particular. The SCMA codebook is configured to set the codebook for at least one layer (i.e., a user) to include a constellation of points having a first grouping of constellation points located at first radial distance from an origin in a complex plane and a second grouping of constellation points located at a second radial distance from the origin. This codebook arrangement provides increased gains at receivers by optimizing the constellation shape to improve the distance between constellation points (i.e., SCMA codebook performance), and in particular more robust performance when encountering amplitude and phase misalignment in uplink (UL) multiple access.

The invention discloses an anti-interference high-precision signal synchronization method based on an access code in a Bluetooth receiver. The method comprises the following steps: taking the access code agreed by two parties as a local training sequence; sampling received signals, and continuously performing delay differential operation on the two sampling values at an interval of one code element period, obtaining a to-be-correlated sequence according to a result of the delay differential operation, performing sliding correlation operation on the to-be-correlated sequence and a local training sequence, searching a peak value of a correlation value, and taking a sampling moment corresponding to the peak value as an initial position of an access code, thereby realizing frame timing synchronization. According to the invention, signal synchronization is carried out by using the Bluetooth access code, interference of other signals in the same frequency band is not liable to occur, the signal detection accuracy is high, and the problem of missing detection or false detection is greatly reduced, so that the working efficiency of the Bluetooth receiver is improved, the Bluetooth communication accuracy and safety are ensured, and the communication system is more stable and reliable.

The present invention discloses a calibration method for parallel multi-channel wireless channel measurement and a calibration system thereof. The transmitting end and the receiving end are disconnected, and are respectively connected to the calibration receiving channel and the calibration transmitting channel, and the calibration receiving channel / calibration transmitting channel cooperates with a measurement channel in air interface measurement, to calibrate a channel response characteristic of the transmitting end and the receiving end. By means of the present invention, a current channel response characteristic between multiple channels can be online supervised in real time, so as to ensure that a measurement error because of an impact of mutual interference between multiple channels can be avoided in the channel measurement process.

The invention discloses a CCSK signal improvement method based on dynamic multi-peak combination, which belongs to the technical field of communication engineering. The method comprises steps: in thecase of signal transmission, the transmitting end adjusts the properties of positive and negative of a to-be-transmitted PN code C(0), the offset s of the to-be-transmitted PN code is adjusted throughcyclic displacement, in a mode of stacking at most M groups of PN codes, the possible states of each group of spread spectrum codes can be enhanced to 2*C<N><M>2*sigma<m=1><M>C<N><m>; and signals arefinally transmitted under assistance of a synchronization strategy. When a receiver receives the signals, under help of the synchronization strategy, the original spread spectrum sequence C(0) is used, the received signals are subjected to correlation operation, and the receiver obtains the original information based on the combination condition of m peaks obtained from the correlation function and the positive and negative condition. The traditional CCSK information transfer mode is not influenced, the information amount is extraly loaded on the basis, the states contained in each spread spectrum code cycle is improved to 2*sigma<m=1><M>C<N><m> from 2*N, and the information transmission rate is greatly improved.

A method and apparatus for detecting synchronization signals. A chip for detecting a synchronization signal generated based on one of a plurality of sequences generated by a sequence generator, the chip comprising a memory and a processor connected to the memory may be provided. The processor may be configured to: receive a synchronization signal; perform a first descrambling of the received synchronization signal for the first sequence by multiplying the received synchronization signal with a first sequence from the plurality of sequences ; performing a second descrambling of the received synchronization signal for a second sequence from the plurality of sequences of the received synchronization signal by changing the sign of at least one element of the descrambling sequence of the first sequence, wherein the first The second sequence is the complex conjugate of the first sequence.

A code division multiple access wireless network (10) network includes a plurality of base stations (11-14) operating asynchronously with respect to each other. Sets of scrambling codes are assigned to the base stations in order to scramble signals transmitted from the base stations. A node (30) of the wireless network receives (102) a first type of measurement report from a wireless terminal (20), the first type of measurement report includes , 13) Observational time difference measurements of signals received by a base station in the active set. A timing reference is determined (103) for each base station using the plurality of observed moveout measurements. receiving (105) from a wireless terminal (20) a second type of measurement report comprising observed time difference measurements collected by the wireless terminal for signals received from base stations (14) not currently serving the wireless terminal and the scrambling code of the received signal. By using the observed time difference measurement in the second type of measurement report and the scrambling code of the signal received from the base station (14) not currently serving the wireless terminal and the determined timing reference for this base station, it is determined The identity of the base station (14) in the measurement report of .

The invention belongs to the technical field of communication and satellite navigation, and in particular relates to a weighted lp correlation synchronization method (p=1 or 2). According to the method, a special weight function is used, and lp correlation coefficients are weighted to effectively suppress the influence of a multipath effect on a traditional lp correlation synchronization algorithm. The analysis shows that the weight function used in the invention has the effect of time domain filtering and can filter out pseudo-peak generated by the multipath effect. In particular, when p is equal to 1, the algorithm provided by the invention has strong robustness to heavy tail distribution noise. A simulation result shows the correctness and validity of theoretical analysis, and shows that in orthogonal frequency division multiplexing (OFDM) and code division multiplexing (CDMA) systems, the method has higher synchronization accuracy and performance than the existing algorithms.

An improved spread spectrum communication system includes a transmitter and a receiver utilizing a pilot channel for the transmission of pure rather than modulated PN codes for code acquisition or tracking purposes with a lower bit error rate. The pilot signal is used to obtain initial system synchronization and phase tracking of the transmitted spread spectrum signal. At the transmitter side, a Walsh code generator, a Walsh modulator, a first PN code generator, a first band spreader, a second band spreader, finite impulse response filters, digital-analog converters, low-pass filters, an intermediate frequency mixer, a carrier mixer, a band-pass filter are used to transmit a spread spectrum signal. At the receiver side, a corresponding band-pass filter, a carrier mixer, an intermediate-frequency mixer, low-pass filters, analog-digital converters, a second PN code generator, an I channel despreader, a Q channel despreader, a PN code synchronization controller, a Walsh code generator, a first Walsh demodulator, a second Walsh demodulator, accumulator & dump circuits, a combiner, and a data decider are used to demodulate a received spread spectrum signal

A control timing synchronization method is executed by a first and a second optical transmission apparatus. The first optical transmission apparatus: superimposes on a main signal and transmits, information of control process details; waits for a first period; subsequently, superimposes on the main signal and transmits, a message giving notification of control start timing; waits for a second period; and subsequently switches a process of the first optical transmission apparatus to a process corresponding to the control process details. The second optical transmission apparatus: acquires the information on the main signal; waits until detection of the message on the main signal, when a process is present that is to be executed by the second optical transmission apparatus based on the information; waits for the second period when the message is detected while waiting for the detection of the message; and subsequently, executes a process corresponding to the information.

The invention discloses a cell search method and device, comprising: performing time slot synchronization; identifying a primary scrambling code group and performing frame synchronization according to a hash value of a secondary synchronization code SSC code number of any number of consecutive time slots; The primary scrambling code group to which it belongs, the primary scrambling code under the primary scrambling code group to which it belongs is obtained, and the cell search is completed. By determining the possible SSC codes of each time slot, the invention searches for the scrambling code group through the hash method, so as to solve the problems of complicated calculation and large storage in the process of searching frame synchronization of existing cells and identifying the main scrambling code group; The scrambling code group identification and frame synchronization process can be completed by calculating the hash value of the SSC code numbers of several consecutive time slots; the number of correlation operations is reduced by about 2 times, and the frame synchronization process is accelerated.