7 results about "Spatial multiplexing gain" patented technology

The invention relates to the technical field of underwater acoustic communication, in particular to an underwater high-speed underwater acoustic communication signal modulation and demodulation method based on multi-beam diversity, which comprises the following steps of: modulating at a transmitting end, generating a space-time coded modulation signal by adopting a multi-beam transducer array, and realizing space diversity by a receiving end through self-adaptive beam forming; modulation adopts a hybrid mode of combining orthogonal frequency division multiplexing and 256-QAM, and the spectrum efficiency is optimized through dynamic subcarrier allocation; and a receiving end demodulates, a three-dimensional compensation matrix is constructed based on an LSTM-CNN joint network, and joint estimation of channel impulse response and Doppler frequency offset is realized. According to the invention, by adopting an eight-unit cross array type multi-beam diversity technology, space signal focusing and multipath interference suppression tasks are completed, and the effect of spatial multiplexing gain is achieved; through combination of 256-QAM and OFDM dynamic subcarrier distribution, a high-spectrum-efficiency transmission task is completed; a time delay-Doppler joint estimation task is completed by constructing a three-dimensional compensation matrix of an LSTM-CNN joint network, so that the channel estimation error is reduced.

The invention provides a satellite downlink hidden transmission method based on an MIMO (Multiple Input Multiple Output) technology. According to the method, satellite hidden transmission in a mobile scene is supported, the processing complexity of a multi-layer weighted fractional order Fourier transform modulation signal method is reduced, and the real-time performance of synchronous distribution is improved; according to the scheme of the invention, a satellite counts state information by using a slowly varying channel between the satellite and a ground station, dynamically calculates a hidden processing matrix according to a minimum mean square error criterion, and pre-processes to-be-transmitted data in real time, so that the anti-interception and anti-cracking capability of downlink transmission data is improved; a hidden processing matrix is introduced into a satellite transmitting end, mass data are mapped to multiple antennas in parallel to be transmitted out at the same time after space-time hidden processing, and the transmission rate of a system and the anti-interception capability of the data are improved by utilizing spatial multiplexing gain provided by an MIMO technology under the condition that the frequency is the same and the transmitting power is not increased.

Various devices, systems, and / or methods perform wireless chip to chip high speed data transmission. Strategies for such transmission include use of improved microbump antennas, wireless chip to chip interconnects, precoding and decoding strategies, channel design to achieve spatial multiplexing gain in line of sight transmissions, open cavity chip design for improved transmission, and / or mixed signal channel equalization.

The application discloses a wireless optical downlink multiple access communication method based on an optical intelligent reflecting surface, and the method comprises the following steps: optimizing at least one user group by using a preset optimization constraint, and determining a multiple access mode between multiple users according to the optimized at least one user group; obtaining optimal optical intelligent reflecting surface parameters and optimal transmission end transmission power distribution coefficients reflected by the intelligent surface; combining the optimal optical intelligent reflecting surface parameters, the optimal transmission end transmission power distribution coefficients and the multiple access mode to generate a corresponding multiple user signal transmission strategy, so as to perform signal transmission by using the multiple user signal transmission strategy. Thus, the technical problem that the wireless optical communication system communication is prone to interruption is solved, the system performance deterioration caused by the non-ideality of the serial interference cancellation is reduced, the spatial multiplexing gain of the wireless optical communication is improved, the channel capacity of the wireless optical communication system is increased, and the multi-user access capability of the wireless optical communication system is improved.

The invention relates to the field of millimeter wave dual-polarized multi-beam antenna arrays, and particularly discloses a compact dual-polarized millimeter wave multi-beam antenna array, which comprises a transition structure, a dual-mode Butler matrix and a dual-polarized antenna, the input end of the transition structure is connected with the radio frequency interface, and the output end is connected with the input end of the dual-mode Butler matrix; the output end of the dual-mode Butler matrix is connected with the input end of the dual-polarized antenna; compared with the traditional discrete design, the high integration level and miniaturization significantly reduce the physical size of the antenna array, the coverage range of the antenna array is expanded, a single array can replace multiple sets of narrow beam antennas, and the number of devices is reduced; spatial multiplexing gain is achieved, multi-user parallel communication or multi-path transmission is supported, and the system capacity and the spectrum efficiency are improved; the dual polarization performance is improved, the polarization multiplexing gain is increased, independent data streams are transmitted through two orthogonal polarization channels under the same time-frequency resource, and the spectrum efficiency can be theoretically improved by two times.

The present application relates to a wireless optical communication method and device based on an optical intelligent reflection surface, wherein the method includes: optimizing optical intelligent reflection surface parameters, transmitter precoding parameters and receiver signal detection parameters for a preset target; performing transmitter precoding by setting a precoding matrix to change the signal distribution at the transmitting end; changing the non-line-of-sight path signal of wireless optical communication by setting and regulating optical intelligent reflection surface parameters; and performing receiver signal detection by setting a signal detection matrix. The present application effectively improves the spatial multiplexing gain of wireless optical communication, reduces the mean square error and bit error rate of the wireless optical communication system, and alleviates the problems of poor communication performance of the wireless optical communication system caused by obstacles.

The present invention relates to the field of underwater acoustic communication technology, and specifically to an underwater high-speed acoustic communication signal modulation and demodulation method based on multi-beam diversity. It includes transmitter modulation, which uses a multi-beam transducer array to generate a space-time coded modulation signal, and the receiver realizes space diversity through adaptive beamforming; the modulation adopts a hybrid method combining orthogonal frequency division multiplexing and 256-QAM, and optimizes the spectral efficiency through dynamic subcarrier allocation; receiver demodulation is based on an LSTM-CNN joint network to construct a three-dimensional compensation matrix to realize the joint estimation of the channel impulse response and Doppler frequency offset. The present invention uses an eight-element cross-shaped multi-beam diversity technology to complete the tasks of spatial signal focusing and multipath interference suppression, achieving the effect of spatial multiplexing gain; by combining 256-QAM with OFDM dynamic subcarrier allocation, it completes the task of high spectral efficiency transmission; by constructing a three-dimensional compensation matrix of the LSTM-CNN joint network, it completes the task of joint delay-Doppler estimation, reducing the channel estimation error.