1677results about How to "Improve spectrum utilization" patented technology

A communication apparatus capable of improving the spectrum usage rate of a system, especially, the spectrum usage rate in connection with both a fast fading and a channel estimation error as compared with the conventional sub-band adaptive method, while reducing the degree of the difficulty in achieving the adaptation, and further reducing the feedback overhead. In this apparatus, a sub-band group AMC parameter selecting part (318) selects an AMC parameter of each sub-band. An adaptive reception control part (503) must control an adaptive demodulating/decoding part (311), while controlling a parallel/serial converter (312) in a stage preceding the adaptive demodulation and decoding processes, and combining received symbols in the same sub-band group for demodulation and decoding.

The invention discloses a multi-modal orbital angular momentum (OAM) vortex electromagnetic wave microstrip array antenna. The antenna comprises a medium substrate, a plurality of array elements, and coaxial feeders and input ports which are corresponding to the array elements. The array elements employ circularly polarized square corner cut patch antennas with truncated corners, the array elements are circumferentially arranged at one surface of the medium substrate at equal distances, a metal thin layer is attached to the other surface of the medium substrate as a grounding surface, and the input ports are connected with the corresponding array elements through the coaxial feed lines. According to the invention, vortex electromagnetic waves with multiple OAM modes are generated simultaneously at one frequency point, and the multi-modal OAM vortex electromagnetic wave microstrip array antenna is suitable for wireless communications such as currently most popular Wi-Fi, ZigBee, Bluetooth and the like. The vortex electromagnetic waves which are good in performance and have dual features of OAM and circular polarization can be generated, the vortex electromagnetic waves are used for multiplexing, multiple coaxial data flows can be sent in one individual channel, and the frequency spectrum utilization rate and the system capacity can be improved to the maximum degree under the condition that the bandwidth is not increased.

The invention discloses a subsequent evolution embedded D2D(device-to-device) implementing method on the basis of IMT-A (intelligent multimode terminal-advanced) standards, and mainly solves the problems that complicated mode selection and single resource allocation strategy during establishment of a cellular network utilizing the embedded D2D technology. The subsequent evolution embedded D2D implementing method includes that a base station acquires state information of a channel between a user and the base station, and forms an adjacent user list by the aid of a global position system GPS; the user percepts adjacent users to acquire a power level list of the adjacent users and uploads the power level list to the base station; the base station forms a full-network channel gain list and generates a D2D potential cluster of the user; the optimal transmission mode is selected for the base station according to the full-network channel gain list, and user's requirement for quantity of service Qos and information of the D2D potential cluster by a joint optimization resource allocation method when the terminal user sends a service request for the base station; and communication is established between the terminal user and a target user according to the selected optimal transmission mode. Compared with conversional cellular communication, the method can assist in increasing frequency spectrum utilization rate, increasing system capacity and reducing overall power consumption of cells.

The invention discloses a millimeter wave large-scale MIMO system multi-user transmission method based on space division multiple access and interference suppression. A base station is provided with a millimeter wave large-scale uniform panel antenna array; a plurality of single-antenna users receive service from the base station on the same time-frequency resource; according to information of wave beam clusters selected by the users, a universal user set is divided into an interference-free user subset and an interference user subset; the space division multiple access transmission method based on double-layer pre-coded codes is adopted to the interference-free user subset, and the transmission method based on interference suppression is adopted to the interference user subset. According to the method, the advantages of two traditional multi-user transmission methods based on space division multiple access and interference suppression respectively are combined, and the bottleneck that in an FDD transmission mode, downlink channel information of a large-scale MIMO system is difficult to obtain is broken through; meanwhile, the computation complexity problem is solved, it is guaranteed that all the users can receive the service from the base station simultaneously, and considerable system performance and speed performance are achieved at limited feedback quantity.

The invention discloses a co-channel full-duplex system based on MPPSK modulation. After the system isolates receiving and sending signals at the radio-frequency head normally, cancellation conducted on leakage self-interference signals is finished on a digital baseband; the cancellation method is conducted after conducting shock filter on MPPSK receiving and sending aliasing signals, extracting and multiplying by coherent carrier, band-pass filtering and digitizing, the result of initial channels of all self-interference channels between the output end of a modulator and a receiver ADC is estimated before formal communication, self-interference offset signals are rebuilt by the adoption of the estimated result, further residual errors are filtered out with the combination of methods of coding rate filtering and double matched filtering of a method of shock filtering-multiplying by the coherent carrier-band-pass filtering-coherent demodulation, and MPPSK receiving signals are demodulated reliably. The co-channel full-duplex system based on MPPSK modulation is free of radio-frequency self-interference cancellation, has low requirements for the dynamic range and sampling rate of the ADC, has high isolation degree for the self-interference signals, and is simple in structure, low in complexity, high in spectrum efficiency and good in demodulation performance.

A method for establishing D2D multicast communication and allocating wireless source thereof in the IMT-A system is used for the data communicating service based on local sharing in the system. The multimedia multicast technology is introduced into the D2D technology for solving the high-speed data sharing request of one mobile terminal on multiple mobile terminals to realize the eNB-assisted D2MD communication under the IMT-A honeycomb network. The method comprises a control signaling interactive progress of the eNB and the D2MD group in the communication establishing process and a wireless source allocating progress of the eNB for the D2MD group. The method for establishing the D2D multicast communication and allocating wireless source thereof in the IMT-A system has the advantages of reducing the eNB load under the IMT-A, and greatly improving the spectral efficiency and throughput capacity of a cell as the D2MD can reuse the spectral source under the premise of not affecting the communication of honeycomb users. The wireless source allocating progress of the eNB for the D2MD comprises three steps of mode selecting, spectrum allocating and power controlling. The method aims at the applying requests of the D2MD users, ensures the QOS (quality of service) of all users as much as possible, is simple in operation, clear in algorithmic logic and low in complexity, and has better promoting and applying prospects.

The invention discloses a dynamic positioning method and device based on UWB and laser ranging combination and belongs to dynamic positioning methods and devices. The dynamic positioning device comprises an ultra-wide band (UWB) wireless communication sensors, a UWB positioning label, laser ranging sensors, an upper computer and a POE interchanger. An ultra-wide band (UWB) wireless communication sensor station is arranged in an area to be detected, the laser ranging sensors are installed on and fixed to the ultra-wide band (UWB) wireless communication sensors, the UWB positioning label is fixed to a target to be detected, and the ultra-wide band (UWB) wireless communication sensors and the laser ranging sensors are connected with the upper computer through the POE interchanger. According to the dynamic positioning method and device based on the UWB and laser ranging combination, the laser ranging sensors are arranged on the ultra-wide band (UWB) wireless communication sensors respectively, so that the relative distance between every two adjacent ultra-wide band (UWB) wireless communication sensors is obtained, in this way, the coordinates of the ultra-wide band (UWB) wireless communication sensors can be re-determined or corrected after the ultra-wide band (UWB) wireless communication sensors are moved, and thus the requirement for dynamic positioning is met. The dynamic positioning method and device based on the UWB and laser ranging combination have the advantages that the dynamic positioning method based on the UWB and laser ranging combination is adopted, positioning is accurate, safety and reliability are guaranteed, installation is easy, and operation is convenient.

The invention relates to a method for transmitting monitoring videos in real time in a broadband digital clustering communication system, which comprises the following steps: a terminal sends a monitoring video request message to a network subsystem; the network subsystem authenticates the terminal, interacts with an information application subsystem to generate quality of service (QoS) policies,and allocates clustering specially-loaded QoS parameters; the network subsystem sends the clustering specially-loaded QoS parameters to a broadband wireless access subsystem, and the broadband wireless access subsystem allocates downlink resources and sends the downlink resources to the user terminal; the user terminal completes the configuration of each layer according to the description of the downlink resources; the broadband wireless access subsystem sends clustering contexts to the network subsystem to establish a completion message; and the information application subsystem interacts with the network subsystem and sends business data streams of the monitoring videos to the user terminal through the network subsystem and the broadband wireless access subsystem. After the embodiment of the invention is applied, the high rate and low time delay of real-time transmission of the monitoring videos can be guaranteed, thereby providing the QoS guarantee.

The invention discloses a UWB-based (Ultra Wideband) precise calibration method for a coal-cutter absolute position and an apparatus. The apparatus comprises a coal cutter body, a coal-cutter positioner, a positioner explosion-proof housing, a host computer, four ultra-wideband (UWB) wireless communication sensors and a POE (Power Over Ethernet) switch; the coal cutter body is fixedly provided with the positioner explosion-proof housing; the positioner explosion-proof housing is inside provided with the coal-cutter positioner; the coal-cutter positioner is inside provided with a UWB positioning label; the ultra-wideband (UWB) wireless communication sensors are fixedly disposed on a hydraulic support at a coal-cutter running end at intervals; and the ultra-wideband (UWB) wireless communication sensors are connected with the host computer via the POE switch. ultra-wideband (UWB) wireless communication is utilized for precise calibration, the anti-interference capability is strong, the transmission speed is high, relatively high bandwidth and relatively low power consumption are provided, and also precise positioning for a downhole coal cutter is provided, and the apparatus is safe, reliable, easy to install and convenient to operate.

The invention discloses a time-varying channel estimation method for a millimeter wave multi-user MIMO system. Based on the sparse characteristics of a millimeter wave channel in an angle domain, a channel estimation method based on compressed sensing is adopted. The method comprises the following steps: (1) modeling a time-varying millimeter wave channel; (2) quantitatively expressing the millimeter wave channel; (3) modeling a time-varying millimeter wave channel estimation problem as a compressed sensing mode; (4) recovering the estimated number of paths, angles of arrival and angles of departure by using a modified block orthogonal matching pursuit (R-BOMP) algorithm; (5) designing an analog precoding matrix and a digital precoding matrix based on the estimated number of paths and angles of arrival; (6) designing an analog merge vector based on the estimated number of paths and angles of departure; and (7) solving a millimeter wave channel matrix based on the number of paths, the angles of arrival and the angles of departure that are estimated as well as the analog precoding matrix, the digital precoding matrix and the analog merge vector that are designed. By adopting the time-varying channel estimation method disclosed by the invention, the accuracy and spectrum efficiency of the millimeter wave channel estimation can be improved.

The invention discloses a method, a device and a system for scheduling resources. The method comprises the following steps: receiving a perception information report RSI of a first user system and a channel status CSI of a second user system from a terminal; and scheduling the resources for a subchannel according to the RSI and the CSI. The device comprises a receiving unit and a resource scheduling unit. The system comprises a base station which is used for receiving the perception information report RSI of the first user system and the channel status CSI of the second user system from the terminal and scheduling the resources for the subchannel according to the RSI and the CSI. Through the method, the device and the system, the system resources are saved, the frequency spectrum utilization rate is improved, and the first user system and a centralized CR system are prevented from mutual interference.

The invention discloses a novel OFDM signal channel estimation combination ICI self elimination method. The sending end pilot frequency design adopts a cluster type pilot frequency OFDM structure with the ICI estimation function. The receiving end is processed according to the following steps: a, converting proceeding FFT of an OFDM sign to a frequency domain, taking out the pilot frequency, and carrying out ICI elimination signal channel estimation; b, carrying out counter modulation after using the signal channel estimation in the first step for coarse balancing; c, using the signal channelestimation in the first step for time domain linear continuous sign signal channel estimation; d, calculating ICI signal channel matrixes through cyclic convolution by using a time domain pulse response structure in the third step, and obtaining ICI interference matrixes; and e, carrying out ICI elimination through combining counter modulation signals in the second step and ICI interference matrixes in the fourth step, and making the judgment after the secondary balancing. The invention solves the problem of influence on OFDM by interference between carrier waves under the condition of lineartime change signal channels, and improves the frequency spectrum utilization rate and the system performance.

The invention discloses a training sequence reconstruction-based channel estimation method and a training sequence reconstruction-based channel estimation system. The method comprises the following steps: acquiring a known channel estimation result; according to the known channel estimation result, constructing linear convolution of former frame transmitted data and a channel and the linear convolution of a transmitted training sequence and a channel impulse response; eliminating inter-block interference of data on a training sequence; obtaining a cyclic convolution, of the training sequence and the channel impulse response, serving as a reconstruction item; according to the reconstruction item, reconstructing the training sequence; and performing channel estimation by utilizing the reconstructed training sequence, and updating a channel estimation result. The method and the system of the invention can ensure that a TDS-OFDM system can also obtain relatively accurate channel estimation when maximum delay extension of the channel exceeds the guard space length of the training sequence, simultaneously improves the accuracy of the channel estimation and improves the spectrum utilization ratio and the mobility performance of the system.

Embodiments of the present application disclose a method and an apparatus for header compression in a network relay scenario. The method includes: receiving, by a relay node, a first header-compressed data packet sent by user equipment or another relay node; encapsulating a transport protocol header for the first data packet and performing header compression for the header to form a second data packet; and sending the second data packet to an eNodeB or a next relay node in an uplink direction.

The invention relates to a method for rotating modulation signals based on an MIMO-OFDM system, the method mutually combines three technologies of MIMO, OFDM and rotation modulation and comprises the steps of firstly introducing a signal modulation subset into rotation and component interweaving which are used for modulating a constellation diagram, dispersing sending data onto different components by rotation modulation and component interweaving, leading an I path component and a Q path component generated by modulation symbols after sending during the transmission process to carry out independent transmission on the respective fading channel, eliminating the correlation between I path and Q path fading factors of sending signals, increasing the advantages of a signal space subset, obtaining gains of the modulation subset, selecting an optimal rotation angle, obtaining the greatest upgrade of transmission performance and simultaneously introducing a space subset of multiple antennas, a frequency subset of an OFDM system and a time-frequency interweaving subset, thereby leading the system to achieve very high transmission efficiency, improving the utilization rate of frequency spectrum, realizing the transmission with high reliability through the subsets, reducing the bit error rate and the frame error rate, being close to the channel capacities of the fading channels and meeting the requirements of development of the next generation of a wireless transmission network.

The invention provides a phase noise compensation method suitable for large line width and high order modulation CO-OFDM system. The method comprises the following steps: performing channel equalization on training symbol data of a receiving terminal after performing Kalman filter on the same in the frequency domain; setting pilot frequency subcarrier data with certain intervals for each OFDM symbol on a transmitting terminal, and performing preset CPE phase noise estimation and compensation at pilot frequency subcarriers in the frequency domain based on extended Kalman filter (EKF); and finally, converting frequency domain data subjected to CPE phase noise compensation into the time domain, and realizing blind ICI phase noise compensation by using the Avg-BL method, then performing pre- judgment, converting the frequency domain data subjected to the judgment into the time domain, applying time domain data and original time domain data of the receiving terminal to time domain unscented Kalman filter, calculating a final phase noise compensation value, and performing compensation. By adoption of the phase noise compensation method, a better phase noise equalization effect is obtained, and the spectrum utilization rate of the system is improved.

The invention provides a utility function based distributed type power control method for a cognitive radio system, belongs to the technical field of wireless communication, and particularly relates to power control used in the cognitive radio system. The invention relates to a compromise solution not only meeting the requirement on protecting a main user, but also supporting the requirement on the service quality of the cognitive user. The scheme is based on the non-cooperative game theory, namely the self-regulation of transmitting power of various CRUs is only needed, so that the defect existing in the conventional distributed type power control that huge information interaction is needed is overcome. By analyzing the geometric characteristics of the utility function, skillfully setting the parameters of the utility function and simultaneously combining the access control, the convergence of power is ensured; simultaneously, by regulating the parameters, the needs for the prior network services are met; in addition, a frame structure and a protocol flow which are suitable for the power control method are designed, and the frame structure and the protocol flow are suitable for any distributed type cognitive radio system, so that the power control method has quite strong practicability.

The present invention discloses a method of wireless digital relay system and transmission time interval selection, which is suitable for time division duplex wireless communication system. The relay system comprises at least a wireless digital repeater, at least a base station, at least a mobile terminal. Linkage between the base station and the wireless digital repeater is divided into a first uplink and a first downlink; the linkage between the wireless digital repeater and the mobile terminal is divided into a second uplink and a second downlink; the linkage between the base station and the mobile terminal is divided into a third uplink and a third downlink; the first uplink and the first downlink adopt the fixed transmission time interval; the second uplink, the second downlink, the third uplink and the third downlink select adaptively the transmission time interval according to the channel quality of corresponding linkage. By supporting flexible transmission interval, the invention uses the optimal transmission time interval in different channel conditions, optimizes transmission efficiency and time delay, and saves transmission power.

The invention discloses a D2D communication method. The method comprises the step that control information and data information are born on a physical resource block, wherein the control information and the data information need to be sent; the control information comprises at least one of a modulation and coding scheme MCS, a redundant version RV and a new data instruction NDI, and at least one of the MCS, the RV and the NDI is mapped on a high frequency part RE in the physical resource block; the data information is mapped on a blank RE except the RE on which the control information is mapped in the physical resource block; and the physical resource block is sent to a target user device in a D2D communication link between devices. The invention further discloses a D2D communication system. According to the embodiment of the invention, by rationally configuring an uplink physical channel of D2D communication, the utilization rate of a high frequency spectrum and the data transmission rate can be improved.