60 results about "Cognitive relay" patented technology

The present invention relates to a method, an apparatus and a computer program product for sensing and communicating in transmission systems with shared spectrum usage, which may comprise e.g. a cognitive relay system. The communication between a transmitter and a receiver occurs in two transmission phases via the assistance of a relay. Sensing is performed at the transmitter during the second transmission phase, thus overcoming the need for dedicated slots for sensing.

The invention provides a recognition relay network trust management device and method based on dynamic evolution. The recognition relay network trust management method comprises a trust perception phase, a trust evaluation phase, a trust evolution phase and a stimulation optimizing phase. In the trust perception phase, node behavior information and user custom requirements are collected, and distinguish contribution degrees of the nodes are described as direct trust perspectives on the nodes. The trust evolution phase is interacted with corresponding phases of other nodes belonging to a perception relay network so as to integrate computional node trust. In the trust evolution phase, node behavior multi-strategy dynamic evolution game is performed, and a node behavior strategy is formulated. In the stimulation optimizing phase, node behaviors are optimized and adjusted, and the nodes are encouraged to obtain better and superior services by improving self trust. The recognition relay network trust management device and method can process conditions of united over-layer attacks and the like in the recognition relay network, achieves fast and stable optimization strategy resolving and effectively restrains selfish and vicious behaviors of the nodes.

The invention discloses a power distribution method used in a cognitive wireless relay network. In the method, a bilateral cognitive wireless network based on amplifying and forwarding relaying protocols is used as a main body. The bilateral cognitive wireless network includes a master user, two secondary users and N relay nodes. On the condition that the power of each node is limited, the suboptimal power distribution method based on the Cauchy-Schwarz inequality enables the system capacity of the secondary users to be maximized and guarantees the service quality of the master user in the whole communication process. Different from a traditional relay network resource allocation method, the Cauchy-Schwarz inequality is introduced into the method, an iterative method is avoided, the calculation complexity is greatly reduced, and the performance approaching to an optimal power distribution method based on an IPM is achieved.

The invention discloses a half-duplex / full-duplex hybrid transmission method of cognitive relay network. The method comprises the steps that: when the power of full-duplex self interference is lower than a threshold, full-duplex transmission is employed, and otherwise half-duplex transmission is employed; in a half-duplex transmission process, one relay transmission frame is divided into two equal time intervals; and in a full-duplex transmission process, time interval division is not carried out on each relay transmission frame. According to the invention, the power of self interference is switched between the half-duplex transmission and the full-duplex transmission, so that the throughput advantage of the full-duplex transmission is utilized, and the bad influences of the self interference on the throughput performance is decreased, so that the method is suitable for a heterogeneous network.

The invention discloses a resource distribution method in a bidirectional cognitive relay network based on energy cooperation. According to the method, a system throughput optimization model is constructed in a condition that causality limitation of the acquisition energy of two users and a relay node and the interference limitation on a main user are satisfied; then, due to problem equivalence transformation, the various node power and cooperation energy joint optimization problem is decoupled into a power distribution problem and a one-by-one time-slot cooperation energy solving problem, which are separated; therefore, the solving complexity of the original problem can be greatly reduced; the decoupled power distribution problem is solved by adoption of an iterative water-filling method; the one-by-one time-slot cooperation energy solving problem is solved in a differential manner; and the result of the original problem is obtained by iteration of the two problems. By means of the resource distribution method disclosed by the invention, multiple technologies, such as cognitive radio, energy cooperation and energy acquisition, can be considered at the same time; and thus, the energy efficiency and the spectrum resource utilization rate can be effectively increased.

The invention discloses a robust wave beam forming method in a multi-antenna multi-user relay cognitive radio network, relating to the technical field of wireless communication. Aiming at the condition that the cognitive radio network channel information has uncertainty, a robust linear wave beam forming method of a cognitive base station and a cognitive relay is designed, interference from or to a main user is suppressed and eliminated, and maximization of weighting rate of a plurality of receiving end users in the cognitive radio network under the most severe condition of the channel is ensured. The invention has the advantages and the characteristics that aiming at a relay-based multi-user multi-antenna complex cognitive communication network that has uncertainty of channel information, the method can be used for effectively simplifying the complex problem needing being solved into a problem capable of being rapidly calculated, therefore, a wave beam forming parameter is rapidly designed, and optimal communication is realized by the relay-based multi-user multi-antenna cognitive radio network under the condition that channel information is incompletely known.

The invention provides a quantum chemistry reaction optimization multi-relay selection method of a cognitive relay network. The method comprises steps of: 1, establishing a cognitive system relay selection model; 2, initializing a quantum molecule set and a system parameter; 3, evaluating the potential energy of all quantum molecules in the set and selecting the measurement state of the quantum molecule with the lowest potential energy as a global optimal solution; 4, arranging the kinetic energy of quantum molecules in a descending order, and performing decomposition reaction, invalid collision, and synthetic reaction; 5, evaluating the potential energy of newly generated quantum molecules, and if the minimum potential energy of the newly generated quantum molecules is less than the minimum potential energy of the previous generation, marking the newly generated quantum molecules as a new global optimal solution; and 6, if the number of iteration times is less than a preset maximum number of iteration times, returning to step 4, otherwise, outputting the global optimal solution. The method balances the primary user constraint condition and non-primary user constraint condition of the cognitive relay network, and chooses a relay selection scheme that maximizes the system throughput based on a quantum chemistry reaction mechanism.

The invention discloses a power distribution optimization method for cognitive relay network energy efficiency maximization. The power distribution optimization method comprises the following steps: firstly, providing a cognitive relay system transmission model, and dividing a signal transmission process into two time slots to acquire a total system transmission rate; secondly, analyzing a spectrum sensing error to acquire disturbance of a cognitive relay system to a primary user; thirdly, in consideration of circuit operation consumption of a cognitive source and a cognitive relay, providingexpressions and constraint conditions of optimization problems; and finally, transforming a mixed integer nonlinear programming problem into a convex optimization problem, and solving an optimal allocation scheme by using fractional programming and KKT (Karush-Kuhn-Tucker) conditions. The invention further provides that a suboptimal algorithm which firstly realizes the optimality under TS1 and then realizes the optimality of TS2, so that the whole process is optimal and the computational complexity is reduced.

The invention belongs to the technical field of mobile communication and particularly relates to an optimal joint power allocation method based on AF (amplify-forward) cognitive relay cooperative transmission. According to the method, in a half-duplex cognitive relay system with a direct link and a relay-aided link coexisting, a direct link transmission time slot is combined with a second time slot of a half-duplex cognitive relay by CDR (coordinate direct-and-relay) transmission of the relay-aided link and the direct link, and interference of the relay on a receiving end of the direct link is eliminated by ANC (analog network coding), so that time slot resources are fully utilized to achieve optimal power distribution among transmitting nodes.

The invention relates to a method for selecting relay nodes capable of enhancing the security performance of a cognitive relay network. With the method adopted in a user communication process, the security performance of the network can be effectively improved, specifically, two important safety indexes, namely, safety interrupt probability and ergodic security capacity, are improved, and the instantaneous channel gain of wiretap channels is not required to be obtained, and only the average channel gain of the wiretap channels is required to be acquired, and therefore, implementation complexity is low.

The invention provides a design method for a secondary user network linear transceiver with a cognitive relay network. The design method comprises the following steps: designing a linear precoder for each secondary user source terminal transmitter to eliminate the interference from the secondary user transmitter to a master user; designing a linear receiver for each secondary user target receiving terminal to eliminate the interference from the master user to the secondary user receiver; and designing beam forming for each secondary user relay to eliminate the interference from the relays to the master user and the mutual interference among secondary users, and maximizing the throughput of the secondary users. The design method can simultaneously eliminate the interference from the secondary users to the master user and the mutual interference among the secondary users, and maximize the throughput of the secondary users. The design method has no limitation for the number of the users and the relays, wherein the number of the users and the relay is greater than or equal to 1. The design method is suitable for the cognitive relay network comprising a single user and a single relay network and any number of the user relays.

The invention discloses a joint resource allocation method of a cognitive relay wireless sensor network, and belongs to the technical field of wireless communication. In the cognitive relay wireless sensor network based on the SWIPT, a sensor subsystem collects energy from a main user signal, and at the same time, the use right of a part of authorized frequency spectrum is exchanged by helping toforward the main user signal so as to transmit a signal of the sensor subsystem. According to the resource allocation method, the power division ratio, the transmitting power allocation and the subcarrier allocation of the sensor nodes are subjected to joint optimization allocation, so that the purpose of maximizing the throughput of the sensor subsystem is achieved, and meanwhile, the target raterequirement of the main system is also considered. The method has the advantages that the throughput of the sensor subsystem can be maximized by reasonably utilizing the energy collected by the sensor nodes and reasonably deploying the subcarriers, so that the system performance is improved.

The invention provides a QoS-based transmission method in a cognitive relay system. The method includes the steps of acquiring a preset number of service transmission source nodes with the highest priority, forming an information channel set according to the preset number of service transmission source nodes with the highest priority, selecting the source node needing the largest bandwidth according to the information channel set, distributing an information channel to the source node needing the largest bandwidth, and selecting a suitable relay node for a destination node according to the distributed information channel. According to the QoS-based transmission method in the cognitive relay system, the source node needing the largest bandwidth is selected from the preset number of service transmission source nodes with the highest priority, and the information channel is distributed to the source node needing the largest bandwidth; services are transmitted through the information channel distributed to the source node, a relay is selected for service transmission of the source node according to an information channel coefficient matrix, therefore, bandwidth requirements are met, user time delay is minimized, the error rate of the system is reduced, and QoS requirements of a user are met on the whole.

The invention discloses a hybrid duplex transmission method in a cognitive relay network based on relay selection. The cognitive relay network includes a pair of transmitter and receiver of authorized users and a pair of transmitter and receiver of unauthorized users, and potential cooperative relays made up of a plurality of idle unauthorized users. First, a potential relay maximizing the sum of end-to-end signal-to-noise ratio of authorized users and unauthorized users is selected as an optimal relay according to instantaneous channel state information. In half-duplex transmission, a relay transmission frame is divided into two equal time slots. In full-duplex transmission, a relay transmission frame is not divided into time slots. When the signal-to-noise ratio received by the relay is lower than a threshold, full-duplex transmission is employed. Otherwise, half-duplex transmission is employed. Transmission is switched between a half-duplex transmission mode and a full-duplex transmission mode according to the signal-to-noise ratio received by the relay. The advantage of full duplex in transmission capacity is utilized, and the adverse effect of self-interference on the performance of transmission capacity is weakened. Therefore, the total transmission capacity of the cognitive relay network is increased.

The invention discloses a selection method of a cognitive network path. The method comprises the following steps: a secondary user source node, a secondary user relay node and a secondary user destination node respectively obtaining various parameters required for analyzing outageperformance of the cognitive network under mutual interference scene of a primary userand a secondary user, establishing an outage probability closed form expression of any one path in a cognitive relay network under a Rayleigh fading channel in combination withinterference limitation allowed by a primary user receiver end, selecting an optimal path of information transmission from a source node to the destination node in the network according to the optimal criterion of system end-to-end outage performance, and selecting a network path by using minimum standard of the cognitive network outage probability. The technical scheme disclosed by the invention gives full consideration to interference factors of the primary user to the secondary user in the cognitive network path selection and takes corresponding measures so as to improve the reasonability of timely selecting the cognitive network path.

The invention discloses a cognitive energy-carrying relay communication method based on multi-time-slot wireless energy collection, and the method comprises the steps that a cognitive network judges whether an authorized spectrum of a main network is idle or not through spectrum sensing, and a cognitive relay node collects the energy transmitted by a main user transmitting end in a wireless energycollection mode if the authorized spectrum is occupied; otherwise, the cognitive network enters an energy-carrying relay communication mode, and the cognitive relay node forwards the information of the cognitive user sending node to the cognitive user receiving node by utilizing the collected energy. The cognitive relay node collects wireless energy through a plurality of time slots and forwardsinformation, so that more energy can be obtained, and the relay forwarding efficiency is effectively improved.

The invention discloses a spectrum sensing and information transmission method with energy collection in a cognitive wireless network, comprising the following steps that: a cognitive user utilizes signals from a main user transmitter for spectrum sensing and energy collection, and uses the collected energy for information transmission; in detecting the main user phase, the cognitive user and N cognitive relays jointly detect whether the main user occupies the spectrum; in the reporting phase, the cognitive user activates the energy collection or information fusion function according to whether it detects that the main user is occupying the spectrum; and in the information transmission phase, the cognitive user performs energy collection or information transmission according to the spectrum sensing final decision result. The invention provides working energy for cognitive users, prolongs the service life of cognitive users, and reduces or eliminates periodic battery replacement while obtaining high spectrum sensing performance.

The invention discloses a mixed duplex transmission method for improving physical layer security in a cognitive relay network. The mixed duplex transmission method comprises the steps of, by a pair of unauthorized users, sharing a frequency band resource with an authorized user in the cognitive relay network with an illegal eavesdropper under the assistance of a cooperative relay and under the interference limitation to a main user; and by the relay, playing a role of confusing the illegal eavesdropper through adding man-made noise while assisting to decode and forward information. One relay transmission frame is divided into two equal time slots during half-duplex transmission. The relay transmission frame is not subjected to time slot division during the full-duplex transmission. When the full-duplex self-interference power is lower than a threshold value, the full-duplex transmission is adopted; otherwise, the half-duplex transmission is adopted. Switching between the half-duplex transmission and full-duplex transmission is realized based on the full-duplex self-interference power, respective advantages of the half-duplex mode and the full-duplex mode are utilized, and the physical layer security of the cognitive relay network is finally improved by increasing the total transmission capacity of the cognitive relay network.

The embodiment of the invention discloses a multiservice-based resource scheduling method and device in a cognitive relay system. According to the multiservice-based resource scheduling method in the cognitive relay system, the service quality requirements of users of different business types are considered aiming at any usable sub-channel corresponding to each business type, the scheduling priority of each user on the usable sub-channel in different sub time slots is calculated according to related information such as service quality parameters and channel capacity of the user or node of each business type, and the usable sub-channel is preferentially scheduled to the user with high scheduling priority. By applying the technical scheme provided by the embodiment, the service quality performance of a multi-business model can be improved while the scheduling fairness is effectively guaranteed, so the communication experience of the cognitive user is improved.

The present invention discloses a multimedia communication cooperative multicast transmission method in a cognitive radio network. The method comprises a first step that a main network sends parameter information to a cognitive relay; a second step that a maximum data bit amount of users in a multicast group is calculated; a third step that the main network determines whether the bit amount of a basic layer meets requirements, if not, a fourth step is carried out, if yes, a fifth step is carried out; the fourth step that the main network combines a cooperative transmission time proportion and a cooperative power that are determined finally, a main user uses a front alpha i part to transmit basic layer data, and a cognitive user uses the left (1-alpha i) part to transmit its own information; the fifth step that the main user uses a front alpha j part to transmit basic layer data, and the cognitive user uses left (1-alpha j) part to transmit its own information; and a sixth step that whether the frame is finished is determined, if not, the second step is carried out, if yes, transmission of the frame data is finished. Through adoption of the method, the system throughput of the main network can be improved effectively, the cognitive network transmission opportunities are increased, the transmission reliability and stability are high, and the method can be applied to a cognitive radio multimedia cooperative multicast system.

The invention belongs to the technical field of wireless communication, and discloses a cognitive user access method and system in a cognitive relay network based on mixed NOMA. No direct transmissionlink exists between the main user transceiver and the cognitive user transceiver. A relay node is needed to assist forwarding, when a main user and a cognitive user perform transmission in a NOMA mode, the target rate of the main user and the target rate of the cognitive user need to be met at the same time, at the moment, the cognitive user and the main user share spectrum resources, and if thetarget rate of the main user cannot be met at the same time in the NOMA mode, the main user transmits the spectrum resources independently. In order to improve the access opportunity of cognitive users, a strategy of combining dynamic power distribution and a dynamic decoding mode is adopted. According to the method provided by the invention, the problem that the cognitive user accesses the authorized frequency band of the main user in the corresponding scene can be effectively solved.

The present invention discloses a cognitive radio-based multi-relay selection method. According to the method of the invention, required information is collected and initialized by a cognitive source node, and the transmitting power of a current relay node is determined; the source node first calculates total interference under a current relay node set, determines whether the total interference exceeds an interference threshold, and calculates the transmission factors of corresponding relay nodes if the total interference does not exceed the interference threshold; a relay node with the largest transmission factor is selected as a cooperative relay; and the source node performs relay node selection and power control according to the criterion of channel capacity maximization, and gradually reduces the power of the relay nodes until assumed relay power is reduced to zero. According to the method of the invention, when the relay node selection is carried out, the transmission factors are adopted as a selection criterion, and therefore, interference on a main user caused by cognitive relay nodes is fully considered, and the channel capacity of a system can be effectively improved; and a quantitative grading method is adopted to perform power control, and therefore, the complexity of the implementation of the method can be decreased.

The invention discloses a cognitive relay network combined relay selecting and resource distributing method capable of supporting mutual information accumulation. Particularly, the method comprises the steps of sharing a spectrum resource by main users and auxiliary users of a cognitive relay network for performing information transmission, occupying a corresponding authorized frequency band by each main user for performing communication, performing communication in a cooperative transmission manner on the condition that communication of the main users is not interfered by each auxiliary user, performing mutual information accumulation by all nodes in the network, receiving a service request of each auxiliary user by a resource management entity, executing a combined relay selecting and resource distributing algorithm, and on the condition that an optimization limiting condition is satisfied, optimizing and determining relay node selection, source node and relay node transmission powers and a sub-channel distribution strategy based on a combined transmission power minimizing principle. The cognitive relay network combined relay selecting and resource distributing method can effectively realize relay selection and node transmission performance optimization in the cognitive relay network and realizes network performance optimization.

The invention discloses a transmission method and a transmission system of a wireless cognitive network based on Nakagami channel fading. The invention provides a transmission method and a transmission system based on Nakagami channel fading wireless cognitive network. Firstly, the capacity of the decoded cognitive relay and the link of the destination node which can correctly decode the source signal are calculated, and the capacity of the eavesdropping channel of each decoded cognitive relay is determined according to the capacity of the decoded cognitive relay and the link of each eavesdropping node. Then the security capacity of each decoded cognitive relay is determined according to the capacity of relay channel and eavesdropping channel. Finally, the decoding cognitive relay with thelargest security capacity is selected as the optimal cognitive relay, and the source signal sent by the cognitive sending node is transmitted to the destination node through the optimal cognitive relay, so that the physical layer security performance of the wireless cognitive network is effectively improved based on more actual channel conditions and eavesdropping state.

The invention discloses a safety relay selection method based on a fuzzy logic algorithm, and belongs to the technical field of a cognitive wireless network. The method comprises the steps that a cognitive wireless network model is established; and a target function and constrained conditions are established for the system and optimization problem solving is performed. The fuzzy logic algorithm and a convex optimization method are compared so that results obtained through the two methods are similar, and the fuzzy logic algorithm only performs simple linear operation without performing complex iteration. Therefore, computation burden of fuzzy logic is proved to be less than that of convex optimization, and feasibility and low complexity of realizing the maximum safety combined rate in a cognitive relay network through the fuzzy logic algorithm can be indicated.

The invention discloses a multi-relay time slot and power joint optimization method based on a DTPS protocol in cognitive SWIPT. A plurality of cognitive SWIPT relay nodes equipped with power divisionreceivers exist in a cognitive SWIPT communication network, a multi-relay time slot and power joint optimization method based on a dynamic time slot power division protocol in cognitive SWIPT is researched, and joint optimization is carried out on a power division factor, a time slot allocation factor and a power allocation coefficient. According to the method, an optimization model is established by taking the maximum network sum rate of the cognitive SWIPT communication network as an optimization target, and the system performance meets the required requirements through optimal relay node selection and joint optimization of the power division factor, the time slot allocation factor and the power allocation coefficient of the optimal relay node. Research shows that with the increase of the first time slot factor and the power division factor, the reachability and the rate of the cognitive SWIPT communication network are increased and then decreased. The method provided by the invention can maximize the reachability and rate of the cognitive SWIPT communication network.

The invention provides a multidimensional resource adaptive allocation-based coordinated cognitive transmission method. The method comprises the steps of (1) configuring an antenna; (2) initializing the transmission period (t) to be 1; (3) acquiring the link rate information by an authorization transmitter PT; (4) taking into account the fairness of relay selection; (5) conducting the coordinated transmission of time domain, frequency domain and space domain; (6) updating the average rate of each cognitive relay STk. According to the technical scheme of the invention, the resource joint-use coordinated transmission of time domain, frequency domain and space domain is comprehensively utilized and the transmission performance of an authorized user is improved. In this way, the communication transmission opportunity is provided for cognitive users, so that the spectrum efficiency is improved. Scheduling weights are calculated based on the historical average rate of cognitive users, wherein a relay of a maximal scheduling weight is selected for realizing the fairness of relay selection. Therefore, a fair communication opportunity is provided for each of all cognitive users. The performances of the cognitive system in the survival time and the energy efficiency of cognitive users are also improved.

The invention discloses a full duplex cognitive relay power distribution method based on energy collection. According to the method, a cognitive relay node performs power distribution on signals received from signals transmitted by a primary user and signals transmitted by a secondary user according to a distribution coefficient [rho], energy resources in a wireless radio frequency environment arefully reutilized while spectrum resource sharing is realized, and the problem that the energy of the relay node is limited is solved. According to the method, a primary user transceiver and a secondary user transceiver adopt an underlay spectrum access mode to perform network spectrum access, and primary and secondary users share a frequency band at the same time. According to the method, energycollection of the relay node is optimized, maximization of the throughput of the cognitive network can be achieved, the relay node adopts a full duplex communication mode, and the method is suitable for occasions with high requirements for the network throughput and time delay, such as the Internet of Vehicles in the current 5G environment.

The spectrum sensing and information transmission method with energy collection in the cognitive wireless network of the present invention, the cognitive user uses the signal from the main user transmitter to perform spectrum sensing and energy collection, and uses the collected energy for information transmission, and detects the main user In the user phase, the cognitive user and N cognitive relays jointly detect whether the primary user is occupying the spectrum. In the stage, according to the final decision result of spectrum sensing, cognitive users perform energy collection or information transmission. While obtaining high spectrum sensing performance, the present invention provides working energy for the cognitive user, prolongs the service life of the cognitive user, and reduces or does not need periodic battery replacement.