7 results about "Shadow fading" patented technology

The present application relates to the field of wireless communication and positioning technology, in particular to a three-dimensional space positioning method based on wireless mesh network and a server; the method comprises determining path loss factor and reference signal strength of free space propagation model by using known distance and signal strength between N reference nodes; selecting M reference nodes with strongest signal received by target node, obtaining coordinates of the M reference nodes and calculating distance from the target node based on the determined free space propagation model; calculating initial coordinate value of the target node by using genetic algorithm based on coordinates of the M reference nodes and measured distance from the target node; calculating final coordinate value of the target node by using improved Gauss-Newton algorithm based on the initial coordinate value of the target node. The present application can effectively reduce the influence of multipath interference and shadow fading on RSSI positioning, and significantly improve the accuracy and stability of three-dimensional positioning.

The invention discloses a wireless communication spectrum space digital twinning method, which comprises the following steps of: generating basic static channel characteristics under a given environment model and a base station deployment condition; wherein the static channel characteristics comprise a path loss distribution characteristic, a shadow fading characteristic and a multipath propagation characteristic; associating the static channel feature with target vehicle information, and generating a single-frame channel feature when a vehicle exists; and capturing dynamic evolution information of channel characteristics in a vehicle movement process, and expanding the single-frame channel characteristics into sequential dynamic channel characteristics to obtain a digital twinborn model of a dynamic scene spectrum space. According to the method, the influence of a dynamic blocking body can be further considered on the basis of static channel generation, channel feature generation in a dynamic environment is realized, and the reality sense and application applicability of digital twinning are remarkably improved.

This invention relates to the interdisciplinary fields of wireless communication network optimization, electromagnetic environment perception, and artificial intelligence computer vision. Specifically, it is a method and electronic device for generating radio maps of complex environments based on a physical constraint latent diffusion model, comprising the following steps: S1, decoupling and constructing a shadow fading gradient map; S2, predicting the shadow fading gradient distribution; S3, compressing the map to a low-dimensional latent space; S4, training the physical constraint latent diffusion model; and S5, inferring and generating the radio map. This invention constructs a hybrid modeling framework of physical prior guidance and latent space generation, introducing a shadow fading gradient map as a strong physical constraint, effectively eliminating the wall-penetrating effect and false signal artifacts. By using a VAE to map high-dimensional data to a low-dimensional latent space for diffusion denoising, it significantly reduces computational resource consumption and GPU memory usage. It achieves the effect of significantly improving the quality of radio map generation and accurately identifying the signal propagation characteristics of complex environments under sparse sampling.

This invention relates to the field of electromagnetic spectrum management technology and proposes a spectrum map construction method based on weighted dynamic allocation tensor ring completion. The method includes: modeling multi-frequency spectrum data as a target spectrum tensor; performing tensor ring decomposition on the target spectrum tensor data to extract TR factors, and generating a spectrum map generation model based on the TR factors; establishing different completion algorithms for path loss and shadow fading scenarios to complete the missing spectrum data in the spectrum map generation model; and weighted fusion of the completion results to construct the final spectrum map. This invention employs different algorithms to complete the missing spectrum data in the spectrum map generation model for different scenarios, thereby improving the robustness of the algorithm under different scenario conditions. Furthermore, by weighted fusion of the completion results from the two algorithms to construct the final spectrum map, it can dynamically adapt to two key factors affecting the construction accuracy, thus accurately constructing the spectrum map.

The invention belongs to the technical field of underwater acoustic transmission, and particularly discloses an MIMO communication cooperative detection method based on hybrid electromagnetic induction and acoustics, and the method comprises the steps: carrying out the signal exchange between a master node and a slave node in a transmitting cluster through a magnetic induction technology, so as to achieve the time-frequency synchronization; generating an MIMO signal adaptive to the underwater mixed cooperation scene based on the synchronized point cooperation relationship between the nodes in the transmitting cluster; transmitting the MIMO signal from the transmitting cluster to the receiving cluster in a k-mu shadow fading channel environment through an acoustic transmission medium, wherein the k-mu shadow fading channel environment is an underwater channel model used for representing a composite line-of-sight effect and a cluster scattering effect; and carrying out signal exchange among nodes in the receiving cluster through a magnetic induction technology to realize time-frequency synchronization, and carrying out signal detection and combination on signals received by the receiving cluster to recover original signals. According to the invention, the reliability and throughput of underwater complex environment communication can be effectively improved.

The invention relates to an RSS (Received Signal Strength) positioning method based on directional gain correction, and aims to solve the problem that a traditional positioning method based on Received Signal Strength performs target positioning under the condition of neglecting antenna directional gain and easily generates system errors in a three-dimensional space. The invention designs an RSS (Received Signal Strength) positioning method based on directional gain correction, which comprises the following steps of: firstly, introducing an antenna directional gain item into a classic logarithmic path loss model so as to more accurately describe the relationship between signal intensity and a space direction; an optimization problem is solved by using an iterative algorithm, and in each iteration, local fixed parameter optimization is performed on the directional gain, and an original non-convex positioning problem is converted into a solvable convex SDP problem. Simulation experiment results show that the positioning precision of the method can approach the Cramer-Rao lower bound, and high robustness is still kept under the condition of serious shadow fading.

The invention relates to a broadband high-frequency ionospheric channel modeling method based on large and small scale dynamic combination. The method comprises the following steps: fitting a path loss model by utilizing actually measured ionospheric channel impulse response of a current link and a least square method; shadow fading is fitted into normal distribution, and a time-frequency related large-scale fading model is constructed in combination with a path loss model; extracting channel parameters of the actual measurement channel impulse response in a time delay domain and a Doppler domain, and constructing a statistical distribution function; generating channel parameters by using a statistical distribution function, constructing a single-mode channel impulse response, and adjusting a multi-mode channel impulse response to obtain a small-scale fading model; and constructing a broadband high-frequency ionosphere channel model by combining a large-scale fading model and a small-scale fading model. According to the method, ionosphere channel large-scale fading time-frequency dynamic analysis is considered, small-scale fading parameter statistical distribution modeling is supported, and the channel modeling precision is improved.