62results about How to "Multiple access" patented technology

The invention provides a multi-carrier spread spectrum power line communication system. Communication equipment in the system comprises a signal transmission device and a signal receiving device; the communication equipment is characterized in that the signal transmission device comprises an encoder, a spread spectrum modulating unit and a carrier modulating unit, which are connected in sequence; the signal receiving device comprises a wavelet filter, a carrier frequency separator, a despreading unit, a data demodulator and a data decoder, which are connected in sequence; when in use, the spread spectrum modulating unit in the signal transmitting device carries out spread spectrum modulation on the data encoded by the encoder, and then the carrier modulating unit carries out multi-carrier modulation on the signal subjected to the spread spectrum in order to meet the orthogonality conditions, and transmits the signal subjected to the spread spectrum to the signal receiving device; the wavelet filter in the signal receiving module carries out wavelet filtering on a received signal, and then the carrier frequency separator carries out frequency separation on each filtered subcarrier, the despreading unit despreads, and the data demodulator demodulates the signal, sequentially, and finally the decoder decodes in order to gain the data.

A method for operating a subscriber unit that communicates with a code division multiple access (CDMA) wireless network is provided. At the subscriber unit, synchronization information is encoded with a CDMA code. The CDMA encoded synchronization information is transmitted from the subscriber unit in discrete repeating intervals. The discrete repeating intervals are separated by other discrete repeating intervals during which the subscriber unit does not transmit synchronization information.

The invention discloses a high-speed wavelet multi-carrier spread-spectrum communication system and method suitable for a 5G network. The system comprises a plurality of communication devices which are in mutual communication and are arranged in a wireless network. The communication devices comprise the signal emission device and the signal receiving device. The signal emission device comprises a coding unit, a spread-spectrum unit, a carrier modulation unit and a parallel-serial conversion unit which are sequentially connected. The signal receiving device comprises a series-parallel conversion unit, a wavelet filtering unit, a dispreading unit, a data demodulation unit and a decoding unit which are sequentially connected. High adaptability is achieved to a time-frequency selectivity wireless channel. Meanwhile, due to the facts that spreading codes with different lengths are used for corresponding to various wavelet subcarriers with different bandwidths, and the spreading codes with the same length are further arranged, so that multiple choices are achieved, the high-speed wavelet multi-carrier spread-spectrum communication system can obtain more higher data rates than that of a conventional multi-carrier spread-spectrum communication system in which fast Fourier transformation is used, and thus the high-speed wavelet multi-carrier spread-spectrum communication system and method are suitable for the high-speed 5G network.

Method for signal generation in broadband wireless communications, comprises: A. modulating, segmenting and serial-parallel converting the signal data to be transmitted, then computing DFT of the serial-parallel converted data so as to transfer them to frequency domain; B. performing block unit modulating processing and block repeat modulating processing on the frequency domain data, then mapping the block units to assigned time-frequency positions; C. computing IFFT of the mapped block units, then adding them to the cycle prefix, thus the random sequences in time domain are generated. Apparatus for signal generation, Method and system for message transmission in broadband wireless communications are also disclosed. The problem of resource allocation and scheduling, and problem of interference coordination and control are solved, the throughput and performance of communication system are greatly improved.

Provided are a wide band-differential chaos shift keying modulation method, a transmitting apparatus adopting the wide band-differential chaos shift keying modulation method, a wide band-differential chaos shift keying demodulation method, and a receiving apparatus adopting the wide band-differential chaos shift keying demodulation method. The wide band-differential chaos shift keying modulation method includes: generating a wide band chaotic signal; delaying the wide band chaotic signal; multiplying the delayed wide band chaotic signal by an information signal to output a multiplied signal; and performing a switching operation so as to alternately transmit the wide band chaotic signal and the multiplied signal. Thus, the invention can be realized without an APLL, a mixer, an FM modulator, and the like, to reduce power consumption and manufacturing cost for the transmitting apparatus. Thus, noise characteristics and security performance can be high, and the wide band-DCSK modulation method can be robust to multi-path.

The invention provides a contention access method and device. In a long-term evolution LTE contention access process, terminal sides can select orthogonal sequences corresponding to terminals from K orthogonal sequences, wherein the K is an integer greater than or equal to 2. MSG3 is expanded through utilization of the selected orthogonal sequences, and the expanded MSG3 is sent to a base station. If a conflict occurs, namely the MSG3 of a plurality of terminals is scrambled through utilization of the same TC-RNTI, the base station can demodulates a plurality of users at the same time according to the expanded MSG3 and issues conflict resolution successful information to the terminals by additionally increasing bits. Through application of the method and the device, the conflict problem generated when the plurality of users access the base station at the same is solved and the conflict solution capability of the base station is improved.

A radio unit (2000) separates a signal from a specific terminal among signals from array antennas (#1-#4) based on a reception weight vector calculated by a reception weight vector calculator (20). A reception response vector calculator (22) derives a reception response vector of a propagation path for the signal from the specific terminal. A transmission response vector estimator (40) regards an estimation result of the reception response vector calculator (22) as a composite waveform of a function of a plurality of frequencies, determined in accordance with a Doppler frequency, and predicts a transmission response vector at a time point of transmission by obtaining coefficients of respective function. A transmission weight vector calculator (30) controls antenna directivity in transmission, based on a prediction result of the transmission response vector estimator (40).

The invention discloses a wavelet multi-carrier spread spectrum communication system and method with frequency changing. The system comprises a signal transmission device and a signal receiving device. The signal transmission device comprises an encoder, a spread spectrum unit, a carrier modulation unit and a parallel-series conversion unit all of which are connected in sequence; the signal receiving unit comprises a series-parallel conversion unit, a wavelet carrier unit, a dispreading unit, a data demodulation unit and a decoder all of which are connected in sequence. The system carries out wavelet reverse transformation on multi-carrier spread spectrum signals according to channel frequency changing to finish the parallel-series conversion, the system can be answerable for a time-frequency selective channel, and the stability of the system is improved; meanwhile, the fast wavelet transformation is adopted, the system has high adaptation and low calculation complexity.

Disclosed is a computer system (100) comprising a processor unit (110) adapted to run a virtual machine in a first operating mode; a cache (120) accessible to the processor unit, said cache including a cache controller (122); and a memory (140) accessible to the cache controller for storing an image of said virtual machine; wherein the processor unit is adapted to create a log (200) in the memory prior to running the virtual machine in said first operating mode; the cache controller is adapted to transfer a modified cache line from the cache to the memory; and write only the memory address of the transferred modified cache line in the log; and the processor unit is further adapted to update a further image of the virtual machine in a different memory location, e.g. on another computer system, by retrieving the memory addresses stored in the log, retrieve the modified cache lines from the memory addresses and update the further image with said modifications. A computer cluster including such computer systems, a method of managing such a computer cluster and a computer program product are also disclosed.

In a subrack with multiple boards, in order to enable a server board and at least one client board of the multiple boards to access a same storage device, an embodiment server board acquires, physical information of at least one physical storage device. Then the server board sends a client board the physical information to enable the client board to establish a virtue storage device and receives a first request for accessing the virtual storage device sent from the client board. The server board convertes the first request for accessing the virtual storage device into a second request for accessing the physical storage device, and sends the second request for accessing the physical storage device to a storage controller connected to the physical storage device in order to enable the storage controller to send relevant data to the client.

A service option overlay for a CDMA wireless communication in which multiple allocatable subchannels are defined on a reverse link by assigning different code phases of a given long pseudonoise (PN) code to each subchannel. The instantaneous bandwidth needs of each on-line subscriber unit are then met by dynamically allocating none, one, or multiple subchannels on an as needed basis for each network layer connection. The system efficiently provides a relatively large number of virtual physical connections between the subscriber units and the base stations on the reverse link for extended idle periods such as when computers connected to the subscriber units are powered on, but not presently actively sending or receiving data. These maintenance subchannels permit the base station and the subscriber units to remain in phase, time and power synchronism while maintaining optimal timing control over synchronization messages. This in turn allows fast acquisition of additional reverse link capacity as needed by allocating additional orthogonal codes within the same code phase and by varying the spreading factor of the codes, as well as by adding additional code phases.

The invention discloses a testing system of an optical fiber network, and belongs to the technical field of optical fiber communication transmission. The testing system comprises a first reference clock chip and a second reference clock chip, and further comprises a central processing unit, an optical transceiver, an FPGA, an EPROM and a JTAG debugger, wherein the first reference clock chip and the second reference clock chip are both connected with the central processing unit, the central processing unit, the EPROM, the JTAG debugger and the optical transceiver are all connected with the FPGA, and the JTAG debugger is connected with the EPROM. By means of the testing system, each module of the FPGA can be tested, configuration programs can be directly written in the EPROM, the engineering period is short, and the development can be conveniently and flexibly realized.

A method for stabilizing a roof-resting vehicle includes the steps of leaning one or more buttress stands against a rear fender area of the vehicle, passing a chain under a rear end of the vehicle from one of the buttress stands to another, tightening the slack from the chain by pulling chain-grab end fittings towards the fenders at the vehicle undercarriage, using a ratchet strap, restraining the chain from sliding off the rear end of the vehicle by attaching a ratchet strap to the chain near a trunk lid of the vehicle, and passing the chain up to the vehicle undercarriage in front of a wheel assembly of the vehicle, attaching a ratchet strap at a base of the one or more buttress stands and tightening, and placing wedges in front of the opposite end of the vehicle, such that the vehicle is stabilized.

One or more embodiments of the present specification provide an anti-interference communication method and electronic equipment, which can solve the problem of reduced communication quality caused byinter-symbol interference and narrowband interference. The electronic equipment includes a memory, a processor, and a computer program stored on the memory and operable on the processor for performingan anti-interference communication method. The anti-interference communication method comprises the following steps that: a signal sending end allocates an information symbol of initial modulation information to a delay-Doppler domain resource grid to obtain a mixed jump symbol signal, carries out inverse symplectic Fourier transform and Hesenberg transform on the mixed jump symbol signal to obtain a time-domain sending signal, transmits the time-domain sending signal to a communication channel; and a signal receiving end receives the corresponding time-domain receiving signal, carries out Wigner transform and symplectic Fourier transform on the time-domain receiving signal to obtain a receiving signal, performs information symbol sequence detection on the receiving signal, and determinescommunication information sent by the signal sending end.

Embodiments of the invention disclose a method and a system for carrying out a terminal comprehensive management service, and a switch. The system comprises a resource pool in which a vBRAS with a service processing capability is deployed by applying an NFV (Network Function Virtualization) technology, and an aggregation switch of a data metropolitan area network, wherein the aggregation switch receives the terminal comprehensive management service sent by an HGU, and sends the terminal comprehensive management service to the vBRAS for processing through a VxLAN tunnel. According to the system, an ITMS service on a BRAS can be separated out, and the separated ITMS service is processed by the vBRAS, so that the access of more broadband users can be realized on the BRAS, and the operation cost is reduced.

The invention provides a grid-based high-precision satellite navigation and positioning service system, which comprises a satellite navigation and positioning resolving module, a user management platform and a terminal user, and is characterized in that the satellite navigation and positioning resolving module is used for resolving reference station data to obtain regional enhanced data information; the user management platform is used for managing and authenticating a terminal user, the authenticated terminal user sends an enhanced data information request to the user management platform, meanwhile, the terminal user sends an approximate position of the terminal user, and according to information uploaded by the terminal user, the user management platform selects the virtual observed quantity of a certain corresponding grid point from the regional enhanced data information as difference information of the user, and sends the difference information and the position coordinates of the grid point to the terminal user. According to the invention, only a fixed number of grid point virtual reference stations are calculated through the satellite navigation positioning calculation module, the calculation is not related to the number of terminal users, and the consumed resources are fixed, so that the resource cost can be greatly saved.

The invention discloses an optical network data card capable of being configured by an FPGA. The optical network data card comprises a first reference clock chip and a second reference clock chip, and further comprises a central processor, an optical transceiver, a PCI-Express interface and the FPGA, wherein the first reference clock chip and the second reference clock chip are both connected with the central processor, and the central processor, the PCI-Express interface and the optical transceiver are all connected with the FPGA; the FPGA comprises an FC data processor, a data-caching mechanism, a PCI-Express processor and a working condition register block, the FC data processor, the data-caching mechanism and the PCI-Express processor are all connected with the working condition register block, the FC data processor is connected with the data-caching mechanism, and the data-caching mechanism is connected with the PCI-Express processor. The optical network data card can achieve Gbs-level data transmission, high-precision real-time big data acquisition, and monitoring and simulation operation of an optical network.

The invention discloses a novel PLC networking structure. The novel PLC networking structure comprises a concentrator, a concentrator carrier module, at least one novel intelligent electricity meter carrier module and at least one electricity meter network, wherein the concentrator carrier module is a CCO end connected with the concentrator via communication; the at least one novel intelligent electricity meter carrier module is respectively connected with the concentrator carrier module via communication; each novel intelligent electricity meter carrier module comprises an STA unit and a Sub-CCO unit which work in parallel; the at least one electricity meter network is correspondingly connected with each novel intelligent electricity meter carrier module; each electricity meter network comprises a plurality of common intelligent electricity meter single carrier modules and a plurality of intelligent electricity meters; each intelligent electricity meter is connected with each common intelligent electricity meter single carrier module via communication; and each common intelligent electricity meter single carrier module is provided with an STA function. The novel PLC networking structure disclosed by the invention has the advantages that more intelligent electricity meters are accessed by additionally mounting the novel intelligent electricity meter carrier module with the Sub-CCO working mode logic in case of using one CCO end.

First normalizing means (12) normalizes first and second code streams (s₁, s₂). First spreading means (13) spreads the output of the first normalizing means (12). STTD coding means (14) subjects the first and second code streams (s₁, S₂) to STTD coding. Second normalizing means (15) normalizes the output of the STTD coding means (14). Second spreading means (16) spreads the output of the second normalizing means (15) by means of the same spreading code as that of the first normalizing means (12). Orthogonal transforming means (17) gives the negative signs to odd chips in a second path spread sequence of each code and exchanges the orders of the odd and even chips. Combining means (18) adds first and second spread sequences of the second path produced by orthogonally transforming the first and second spread sequences of the first path. With this, by using the orthogonality of the transmitted sequences at the receiving side, the reception signal can be detected with a lower complexity.