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

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 a frequency-modal-empty state multi-dimensional hybrid wireless communication signal modulation method for further improving communication achievable rate. The method comprisesthe specific steps as follows: (1) binary bit stream blocking; (2) constellation modulating and mapping; (3) subcarrier, orbit angle momentum modal modulating; and (4) signal transmitting after spacemodulation. By using a three-dimensional modulation space formed by a transmitting antenna, the orbit angle momentum modal and the sub-carrier, three additional modulation dimensions are provided forthe traditional modulation method, the advantages of being low in system computing complexity and high in communication achievable rate are provided; and the communication achievable rate can be greatly improved even if the antenna number at the transmitting end is small.

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 provides a multi-antenna base station transmission method and device independent of pilot frequency for solving a problem in the prior art that an increase in channel capacity is suppressed seriously because a required pilot and feedback overhead become unacceptable due to a substantial increase in the number of base station antennas. The pilot-independent multi-antenna base station transmission method comprises the following steps of: pre-defining a pre-coding vector set V = [v1, v2, ... vN] consisting of N pre-coding vectors; broadcasting all the pre-coding vectors in the pre-coding vector set V to all users one by one; and S103: calculating S scheduled users k1, k2 ... ks according to bits {a11, ... akn, ... aKN} fed back by all the users, enabling the system to allocate the pre-coding vectors vk1, vk2,..., Vks to the S scheduled users respectively, and enabling the system to use the pre-coding vectors vk1, vk2,... Vks to serve the S users simultaneously and respectively. The method and device do not depend on pilot, can be used as a transmission scheme of a large-scale multi-antenna system in a frequency division duplex mode, and significantly reduce the huge overhead required by the estimation and feedback of channel state information at a transmitting end in a traditional scheme.

The invention discloses a mode switching method for reducing training overhead in an intelligent reflective surface assisted communication system. The system includes a single-antenna base station, a single-antenna user terminal and an intelligent reflective surface composed of N reflective elements, wherein the single-antenna user terminal is directed to The single-antenna base station transmits data, but the user-base station direct link is blocked by obstacles, and the data can only be sent to the single-antenna base station through the smart reflector; the controller determines the appropriate reflection scheme for the smart reflector and dynamically adjusts its phase To increase the achievable data rate of the system; and the necessary information for phase shift adjustment can be obtained through uplink training at the base station and transmitted to the controller of the smart reflector through the control link. The method comprehensively utilizes statistics and instantaneous channel state information, and properly selects an intelligent reflection surface reflection scheme, which can effectively reduce training overhead and improve system performance.

The invention discloses a downlink beam forming method of a VLC (Visible Light Communication) MU-MISO (Multiple Users-Multiple Input-Single Output) system, and belongs to the technical field of visible light communication. According to the method, firstly, the optimization solution is carried out on a beam shaping matrix optimization model by a bi-level iterative method, thus obtaining an optimized beam shaping matrix; and then carrying out downlink beam forming according to the beam shaping matrix. The invention also provides a beam shaping matrix optimization model taking a maximum reachable rate as an optimization target. The invention also discloses a downlink beam forming device of the VLC (Visible Light Communication) MU-MISO (Multiple Users-Multiple Input-Single Output) system and the VLC (Visible Light Communication) MU-MISO (Multiple Users-Multiple Input-Single Output) system. Compared with the prior art, the method, the device and the system have the advantages of low hardware demand and the reachable rate of the system can be further improved.

Embodiments of the present invention provide a communication system, method, device, and storage medium. The system includes: a base station, a reflecting surface, and multiple user terminals, wherein each user terminal broadcasts a pilot signal; the base station receives the first received signal, By analyzing it, calculate its corresponding channel state information, and then determine the target configuration parameters of the reflective surface; the reflective surface adjusts its own configuration according to the target configuration parameters, and obtains the adjusted reflective surface; the base station sends multiple pieces of data to be sent The information is encoded into a data packet, and the base station signal carrying the data packet is broadcast; the adjusted reflector receives the second received signal, and the reflected signal is obtained by applying reflection phase shift and reflection amplitude to it; each user terminal is connected to the third The signal is received, and by decoding it, the data information to be sent corresponding to the user terminal is obtained. In this way, the transmission delay of the communication system can be reduced while controlling the bit error rate as much as possible.

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 present invention discloses a method for maximizing average energy efficiency power allocation in a delay-insensitive D2D communication system, which is carried out as follows: firstly, a base station selects a cellular user through a scheduling algorithm and shares its frequency resources with a selected D2D link; then The scheduled and activated cellular users and D2D users feed back channel state information to the base station; then the base station calculates the optimal power allocation scheme for the average energy efficiency of the D2D link that is not sensitive to delay according to the channel state information uploaded by the cellular users and D2D users ; Finally, the sending end of the D2D link completes the data transmission according to this power allocation scheme. The present invention can be effectively applied in actual scenarios. According to the optimal power allocation scheme calculated by the base station, the average energy efficiency of cell edge users that are not sensitive to delay can be effectively improved, and the power consumption of D2D terminals can be reduced while restraining its interference to cellular users. , thereby increasing the average spectrum utilization.

The invention discloses a hybrid precoding design method using a single-bit analog-to-digital converter MIMO system. The scheme can combine a hybrid precoding structure and a low-precision analog-to-digital converter in the MIMO system to effectively reduce energy consumption of the MIMO system and implementation costs. The invention fully considers the hybrid precoding structure and the single-bit analog-to-digital converter structure, and performs mathematical modeling on them. In the application, the proposed iterative algorithm can be used to optimize the design of the analog precoder and the digital precoder to maximize the system's overall attainable rate. The present invention has the advantages of reducing system implementation cost and energy consumption, and maximizing the attainable rate of the whole system through the design of the digital precoder and the analog precoder. This advantage makes the proposed hybrid precoding design scheme have a wider range of application scenarios, thus making the MIMO system more feasible in practice.