34results about How to "Increase reachable speed" patented technology

The invention belongs to the technical field of digital information, and provides a beam forming method and system for a multi-user millimetre-wave communication system. The beam forming method comprises the following steps of: performing beam forming training of a user side according to a preset beam forming training algorithm so as to obtain a beam forming training result; according to the beam forming training result, judging whether a conflict user side exists or not, wherein the conflict user side is a user side for downlink sending of a beam forming vector by adopting the same base station side; if so, selecting a beam forming vector pair to be subjected to downlink sending/receiving for the conflict user side so as to obtain a beam forming vector index to be subjected to downlink receiving of the conflict user side; and sending the beam forming vector index to be subjected to downlink receiving of the conflict user side to the conflict user side, such that the conflict user side searches the corresponding beam forming vector to be subjected to downlink receiving according to the received index. A conflict judging process is added into the traditional beam forming mechanism; therefore, the beam forming vector is re-selected for the conflict user side; and thus, the achievable rate of the conflict user side in the traditional beam forming training method is increased.

The invention discloses a direct-current offset optimization method of a multi-carrier visible light communication system. The optimization method aims at finding the direct-current offset Bdc which enables bit error probability of the system to be the lowest, and each subcarrier power sigma 2. The optimization method comprises the following steps: firstly confirming systematic parameters according to required indicators, hardware restrictions and the working environment, then setting intermediate variable a= Bdc/sigma, using an iterative algorithm for solving the lowest bit error probability aopt of the system, finally, considering a light power restriction condition and an electric power restriction condition, confirming the Bdc and the sigma 2 according to the aopt, and completing the optimal design of the system. The optimized method can rapidly and precisely obtain the optimal parameter design scheme, enables the visible light communication system based on DCO-OFDM to obtain the lowest bit error probability, achieves the biggest reachable speed rate, and meanwhile is small in calculated amount, easy to achieve and high in precision.

The invention discloses an information energy cooperative beam forming method based on a cognitive two-way relay network. According to the invention, the secondary user sending ends of multiple antennas collect energy from the signals of a primary user according to a power allocation scheme so as to forward the signals of the primary user and send their own signals. The purpose of the invention isto design beam forming matrixes, vectors and power allocation factors suitable for secondary user sending ends, so that the achievable rate at each secondary user is enabled to be maximal. Herein, the ideal channel state information for all known links of the secondary user sending ends is considered, and an optimization scheme based on Charnes-Cooper translation and one-dimensional search is provided. Through introducing the semi-definite relaxation method, an original optimization problem is converted into a convex semi-definite optimization problem. After that, the interior point method isadopted to solve and obtain an optimal beam forming matrix and a vector. According to the invention, through the cooperation of the information and the energy, the spectrum and energy insufficient problem can be alleviated to a certain degree, so that the system performance is improved.

The invention discloses an IRS-assisted MISO system performance optimization method for hardware distortion, and the method comprises the steps that a multi-antenna base station wide linear precodes messages of M information users, generates a baseband transmission signal, processes the baseband transmission signal into an asymmetric Gaussian signal, and generates an output signal through a high-power amplifier; with the assistance of an intelligent reflecting surface, the multi-antenna base station transmits the output signal generated by the high-power amplifier in a broadcasting manner, and controls the phase shift of a reflecting element in real time through a controller on the intelligent reflecting surface; the rates of M information users are decoded; and by taking the rates of the M information users as performance evaluation, a base station beam forming vector and a phase shift vector at an intelligent reflecting surface are optimized under the condition of satisfying the total power constraint of the base station, and the minimum reachable rates of the information users are maximized to complete performance optimization. According to the invention, the IGS is used for transmission, so that the reachable rate of the information user is further improved.

The invention discloses a SWIPT system performance optimization method and system based on intelligent reflecting surface assistance, and the method comprises the steps: decoding information and collecting energy through a power divider at the same time, introducing RIS to compensate the serious path loss and shadow fading, and employing IGS to compensate the loss caused by unavoidable asymmetric hardware distortion; the objective is to maximize the minimum achievable rate of a user and a rate energy domain with weight by jointly optimizing active and passive beamforming vectors and a power distribution coefficient under the constraint of AP power budget and energy service quality requirements of the user. According to the method disclosed by the invention, the influence of the HWI and the interference among the users are compensated by adopting an asymmetric Gaussian signal scheme, the maximum rate and the minimum rate are remarkably improved, and the performance optimization problem of the SWIPT system assisted by the RIS with the HWI is solved.

The invention provides a pilot scheme self-adaptive selection method of a full-duplex bidirectional massive multiple input multiple output relay network. The method comprises the steps of 1, establishing a symmetrical full-duplex bidirectional massive multiple input multiple output relay network; 2, sending state information to a relay by all user terminals; 3, collecting statistic information of large-scale fading between all users and the relay by the relay; and 4, self-adaptively selecting a first pilot scheme or a second pilot scheme by the relay through a calculation judgment system. According to the method provided by the invention, the prior statistic information of large-scale fading is applied; the calculation is convenient and rapid; the channel coherence time is utilized fully; and the reachable speed of the system is clearly improved.

The invention discloses an average energy efficiency maximization power distribution method in a delay insensitive D2D communication system. The average energy efficiency maximization power distribution method comprises the following steps: firstly, a base station selecting cellular users through a scheduling algorithm and sharing frequency resources of the cellular users to a selected D2D link for use; then the dispatched and activated cellular users and D2D users feeding channel state information back to the base station; then, the base station calculating a power distribution scheme which enables the average energy efficiency of the D2D link insensitive to delay to be optimal according to the channel state information uploaded by the cellular users and the D2D users; and finally, the D2D link sending end completing data transmission according to the power distribution scheme. The method can be effectively applied to an actual scene, the average energy efficiency of cell edge users insensitive to delay is effectively improved according to the optimal power distribution scheme calculated by the base station, the D2D terminal power consumption is reduced, meanwhile, the interference of the D2D terminal power consumption to cellular users is restrained, and then the average spectrum utilization rate is improved.

The invention provides a deep reinforcement learning (DRL)-based semi-parallel method used in a reconfigurable intelligent surface (RIS)-assisted user centralized cellular removal (UCCF) system. According to the method, an optimization problem is decomposed into two iterative sub-tasks, namely an access point (AP) and user equipment (UE) association (AUA) sub-task and a transmit power and RIS reflection coefficient management (PRCM) sub-task. The method specifically comprises the following steps: adopting a binary particle swarm optimization (BPSO) algorithm for integer nonlinear programming AUA; for a PRCM of multi-continuous variable joint optimization, a parallel algorithm based on a DRL is provided, a double-delay depth deterministic strategy gradient (TD3) algorithm is adopted to improve convergence, and a new state preprocessing mechanism is provided. According to the method, a plurality of variables are optimized by adopting a DRL-based semi-parallel method, the limitation of solving an NP-hard problem by a traditional algorithm is overcome, the accuracy is improved, and meanwhile, the intelligent method can be quickly adjusted when facing environment change without a large amount of priori knowledge.

The invention discloses a multi-relay opportunity beam forming method. A signal sent by a transmitting end is amplified through relays and forwarded to a user of a receiving end; before data transmission, the system selects an optimal relay and an optimal user according to information fed back by the user, and then information transmission is carried out; in the transmission process, in order to maximize the reachable rate of the system, the system reasonably dispatches the power allocated to the relay and the power allocated to the user. According to the method, the performance saturation point of the system is improved, the situation that a user at a receiving end cannot receive data can be better avoided, the communication performance of the system is improved, the reachable rate in the system reaches the maximum, and high-speed communication is achieved.

The invention provides a moving target tracking method based on an adaptive beam, and aims to improve the tracking precision of a base station on a high-speed moving target and reduce the system overhead and time delay, and the method comprises the following implementation steps: constructing a moving target tracking scene, predicting the movement track of the moving target by the base station, and determining the optimal beam orientation; the base station calculates the optimal beam width, the base station calculates the number of code words in the codebook according to the optimal beam width and generates the codebook, the base station conducts self-adaptive adjustment on the beam, and the base station obtains the tracking result of the moving target. According to the invention, tracking is carried out by using the adaptive wave beam, so that the problem that the tracking precision is reduced due to sharp increase of the training frequency under the condition that the speed of the moving target is relatively high is avoided, the problems of high system overhead and long time delay in the prior art are solved, and the real-time performance of wave beam tracking is further improved.