8 results about "Physical layer network coding" patented technology

Methods and systems for physical layer network coding based on two-dimensional (2D) joint coding are described. In some methods, first and second packets are obtained. A set of one or more cross-packet check blocks is generated, where each cross-packet check block is generated based on a set of cross-packet bits including at least one bit from each of the first and second packets. At least one cross-packet check block is transmitted to a first communication node.

The application discloses a key default security information exchange method, system, device and medium based on physical layer network coding and block chain in Internet of Vehicles, and the method comprises the following steps: constructing a block chain network; registering an on-board unit (OBU); initiating a data exchange request; authenticating the OBU; and exchanging data. The system, device and medium are used for realizing the key default security information exchange method based on physical layer network coding and block chain in Internet of Vehicles. The block chain technology is applied to identity authentication of Internet of Vehicles, and the data exchange between OBUs is carried out by using physical layer network coding, so that the security and confidentiality are high, and the eavesdropping attack and privacy leakage can be prevented at the same time.

The invention relates to the technical field of data processing, in particular to an on-satellite remote sensing data task-oriented cross attention fusion compression wireless transmission method, which comprises the following steps that: an intelligent agent takes metadata and channel state information as a state space and takes a parameter adjustment strategy of a cross attention mechanism as an action space; the output decision dynamically adjusts the interaction degree of different modal original data stream features, and the adjusted features are compressed to generate a compressed data stream; a compressed data stream is input into a wireless transmission digital twinborn model constructed on a satellite, a carrier sensing multi-channel access protocol is adopted in an actual transmission stage, and the size of a protocol backoff window is dynamically adjusted by the digital twinborn model according to a rehearsal conflict probability and is optimized by combining a channel capacity change trend prediction result. And finally sending the composite signal of the physical layer network coding. According to the invention, through task-oriented data processing, intelligent compression and digital twinborn rehearsal, the spectrum competition conflict of satellite multi-modal data concurrent transmission is solved.

A method for intelligent coding and mapping of underwater acoustic physical layer network coding is proposed, relating to the field of underwater acoustic communications. Combining the BP algorithm with deep learning, a superposition signal intelligent coding and mapping method (FBENet) with low coupling to channel information is proposed. The feature extraction module effectively extracts abstract features of the input information through a convolutional neural network (CNN). The bidirectional equalization module utilizes Bi-LSTM network neurons to equalize inter-carrier interference (ICI) in a time-frequency dual-extended channel, correcting the posterior probability distribution of subcarriers by simulating the sum-product message passing process of the BP algorithm. The probability output module outputs the probability distribution of the transmitting codeword combination for each subcarrier through a fully connected network for subsequent network coding. The network model's loss function uses a multi-classification cross-entropy loss function. During the training phase, as the model calculates parameter updates, the difference between the sample and the output decreases until it reaches a threshold, indicating successful training.

The application discloses a kind of underwater acoustic physical layer network coding symbol synchronization methods, belong to underwater acoustic communication and networking field.Three-node underwater acoustic PNC symbol synchronization mechanism is designed: preset relay node R is expected to the fixed transmission delay T of two terminal nodes A and B S , two terminal nodes A and B reach this expected time as target, utilize clock information in data transmission process to estimate downlink propagation delay, obtain the waiting delay τ A (k) and τ B (k) required before multiple access of terminal nodes A and B in each round PNC transmission process, realize the symbol synchronization of each round PNC transmission;Establish asymmetric link Kalman filter clock synchronization algorithm, for providing accurate clock information for PNC symbol synchronization mechanism, improve the synchronization accuracy of PNC symbol synchronization mechanism.Reduce the time slot overhead of underwater acoustic network, improve the performance of entire underwater acoustic network.

The present invention discloses a method for maximizing the energy efficiency of a drone relay system based on physical layer network coding. The method comprises the following steps: mathematically modeling the energy efficiency maximization problem of the drone relay system, converting the energy efficiency maximization problem into a mixed-integer non-convex optimization problem, decoupling the non-convex optimization problem into subproblems for solving transmission scheduling and associated variables A, transmission power variables P for drones and UDs, and drone trajectory variables Q; and solving the subproblems by combining a block coordinate descent algorithm, a continuous convex optimization method, and a Dinkelbach algorithm. The energy efficiency maximization solution provided by the present invention can balance the throughput of the drone relay and the energy consumption caused by its flight, minimizing flight energy consumption while maximizing communication throughput.

The invention discloses an unmanned aerial vehicle relay system energy efficiency maximization method based on physical layer network coding, and the method comprises the steps: carrying out the mathematical modeling of an energy efficiency maximization problem of an unmanned aerial vehicle relay system, and converting the energy efficiency maximization problem into a mixed integer non-convex optimization problem, decoupling the non-convex optimization problem into a sub-problem of solving a transmission scheduling and association variable A, a sub-problem of transmission power variables P of the unmanned aerial vehicle and the UD, and a sub-problem of a trajectory variable Q of the unmanned aerial vehicle; and solving the sub-problem by combining a block coordinate descent algorithm, a continuous convex optimization method and a Dinkelbach algorithm. According to the energy efficiency maximization scheme provided by the invention, the relay throughput of the unmanned aerial vehicle and the energy consumption caused by flight of the unmanned aerial vehicle can be considered, and the communication throughput is improved to the greatest extent while the flight energy consumption is reduced as much as possible.

The present invention discloses a bidirectional relay NOMA transmission method based on network coding and backscattering, including: setting two cellular users and a relay user without direct links between each other, and distributing a backscattering device cluster around each of the two cellular users; in the first time slot, the cellular users respectively perform power domain superposition coding on the signals they need to send to the relay user and the other cellular user, and broadcast them to the relay user; at the same time, the cellular users receive the signals reflected by the backscattering devices around them; in the second time slot, the relay user encodes the signals that the two cellular users need to send to each other into a composite signal through the physical layer network coding technology, and uses the downlink NOMA to send the composite signal and its own signal to the cellular user; while the cellular user and the relay user communicate in pairs, the signals from the surrounding backscattering devices are decoded. The present invention can expand the communication coverage and improve the system spectrum efficiency.