361 results about "Noma" patented technology

Switching between Orthogonal Multiple Access (OMA) and Non-Orthogonal Multiple Access (NOMA) modes of a user equipment (UE) can be determined and indicated by a gNB to a UE at an RRC connected state using one or more of the following schemes: at an RRC (Radio Resource Control) layer with an RRC configuration message, at a MAC (Medium Access Control) layer with MAC CE (MAC control element) signaling, at a PHY (Physical) layer with DCI (Downlink Control Information) signaling, jointly with RRC configuration and DCI signaling, and / or jointly with RRC configuration and MAC CE signaling. The OMA or NOMA mode that the UE operates after the transition may be requested by the UE, indicated by the gNB, and / or may be based on one or more rules for OMA-NOMA switching.

The invention discloses an NOMA technology based cooperative multicast transmission method. The method comprises the steps that S1) a base station constructs a unicast user candidate set; S2) the base station selects optimal unicast users d<n*> and multicast users from the user candidate set, and the selected users access the network at the same time; S3) the base station sends signals SBS(t) to all the multicast users and optimal unicast users d<n*>; S4) after receiving the SBS(t), the unicast users d<n*> decode multicast user signals S0(t), a step S5) is turned to if decoding succeeds, and otherwise, a step S6) is turned to; S5) the unicast users d<n*> remove the S0(t) from the SBS(t) via a successive interference cancellation technology, and then decode expected signals S1(t) and forward the multicast user signals, the multicast users receive the forwarded signals and merge the forwarded signals with signals received from the base station, and expected signals S0(t) are decoded; and S6) the unicast users d<n*> and the multicast users decode the signals SBS(t) to obtain the expected signals S1(t) and S0(t) of the themselves directly and respectively. Thus, the anti-interruption performance of multicast communication can be improved, transmission opportunities are provided for the unicast users, the spectral efficiency is improved, and the method can be applied to a multimedia multicast transmission system.

Systems and methods of providing a NOMA transmission are described. A UE, may determine, while using grant-free UL NOMA transmission in a slot to a gNB, whether to transmit to the gNB an indication for a grant-based UL NOMA transmission in a later slot. In response to a determination to continue grant-free transmission, if the grant-free transmission comprises repetitions of a TB transmission, a power of the TB transmissions is dependent on a number of repetitions remaining and a total number of repetitions or on higher layer signaling from the gNB. A grant-based transmission request and grant-free UL data are sent to the gNB in the slot if the grant-based transmission is to be used in the later slot, and the repetitions of the TB transmission in accordance with the power are sent if the grant-free transmission is to be used in the later slot.

The present disclosure relates to a sparse-coded ambient backscatter communication method and a system. According to the sparse-coded ambient backscatter communication method, in an ambient backscatter system including an access point and a plurality of sensor nodes, each sensor node transmits a code word in a non-orthogonal multiple access (NOMA) manner using sparsity of a signal by a duty cycling operation and the access point detects a superimposed signal transmitted in the NOMA manner by an iterative decoding method in which a dyadic channel and intersymbol interference are reflected. The present disclosure may reduce the implementation cost by reducing the number of impedances required to modulate data of a batteryless sensor node in an Internet of Things environment and utilize the dyadic backscatter channel to detect a signal, thereby providing massive connectivity of the access point.

The invention provides a secure communication method in a non-orthogonal multiple access network assisted by an intelligent reflecting surface, and belongs to the field of multi-user non-orthogonal multiple access network security. By superposing a proper amount of artificial noise in transmitted NOMA information and jointly optimizing an IRS reflection phase, a transmitted beam vector and an artificial noise vector, the sum of transmission rates of legal users is maximized. In addition, the artificial noise signal for controlling transmission can be completely eliminated by a serial interference elimination technology at each legal user side, so that eavesdropping is effectively inhibited under the condition of not influencing legal receiving. Compared with an OMA (Orthogonal Multiple Access) scheme without artificial noise and assisted by a traditional reflecting surface, the invention has the advantages that the network security performance can be remarkably improved, and the application value is very high.

The invention discloses a relay-assisted non-orthogonal multiple access cooperative network security communication method, and belongs to the field of network security. According to the method, a relay R is used as an information forwarding node; the communication process is divided into two stages: the first stage is the process from two information sources T1 and T2 to a relay R, and the secondstage is the process that information is transmitted from the relay R to target users U1 and U2 in a downlink mode; artificial noise is introduced in the second stage, the eavesdropping process of aneavesdropper is disturbed, and the safety of information transmission is guaranteed. And the two information sources T1 and T2 continue to send the next information, the communication process is stilldivided into two sections for transmission, and the transmission is forwarded by the relay R. According to the invention, on the one hand, the information transmission link of an NOMA network formedby a cooperative relay is established; on the other hand, the artificial noise is introduced by using the physical layer security technology, so the security of the communication system is improved, the security interruption probability is reduced, and an important technical reference is provided for the security performance design of the NOMA network.

The invention discloses a non-orthogonal multiple access decoding method for a power domain. A superimposed modulation signal (formula) is regarded as an overall constellation diagram, an information symbol X2 is decoded and recovered by utilizing a receiving signal Y1 through a high order modulation soft decoding algorithm, and a signal-to-noise ratio of decoding at this time is (formula). When a channel decoder fails to recover the information symbol X2, the soft decoding information of the obtained information symbol X2 is taken as prior information to assist decoding of an information symbol X1. The method aims at the characteristics of an NOMA system and provides a novel method for decoding at a near user place. The probability of failure of decoding a signal of a user 2 at a place of a user 1 can be reduced, so that the performance of decoding a signal of the user 1 at the place of the user 1 is further improved. The better decoding performance is obtained at the cost of increase of decoding complexity. The method can be also applied to decoding at a far user place.

The invention relates to an intelligent reflector-assisted SM-NOMA system resource allocation method, which belongs to the technical field of communication, and comprises the following steps of: for an intelligent reflector-assisted SM-NOMA system, carrying out dynamic user grouping by considering the effective channel gain of each user; and according to the maximum transmitting power constraint of the base station and the user and the incident signal phase shift constraint of the intelligent reflection unit, establishing a power distribution model taking maximization of the system sum rate as a target. The system resource allocation algorithm provided by the invention can effectively improve the system sum rate and reduce the system error rate on the premise of ensuring the maximum channel difference of each group of users.

The invention provides a beam design method based on safety energy efficiency in a satellite-ground integrated network, which is used for solving the low system safety energy efficiency of a downlinkof the existing satellite-ground integrated network. The method comprises the following steps: firstly, forming a high-gain directional beam by adopting analog precoding; secondly, designing digital precoding to eliminate inter-user interference; and finally, proposing a joint optimization problem of transmitting power and a power splitting coefficient, so as to maximize the safety energy efficiency of the system and meet the service quality constraint of each user at the same time, and the interference limitation of a satellite ground station and power consumption limitation of a base station. In order to solve the problem, an iterative algorithm based on Dinkelbach and continuous convex approximation SCA is provided to obtain the solution of the problem, and the convergence efficiency ofthe safe transmission rate of the system is improved. According to the method, a millimeter wave large-scale MIMO NOMA system is combined with the SWIPT technology in the ground network, and the basestation provides services for a plurality of users and protects the satellite ground station from interference.

The invention relates to an IRS-NOMA system beam forming optimization method based on SDR, and belongs to the field of data processing. The method comprises the following steps: S1, allocating a beam to each of all users, and distinguishing different users according to the power; S2, establishing a system model and a QoS problem model; and S3, iteratively solving a beam forming vector and a phase shift matrix by using an alternative optimization idea. According to the invention, an NOMA downlink beam forming algorithm assisted by an intelligent reflecting surface is researched. Compared with a traditional NOMA system, the model provided by the invention has more loose requirements on channel conditions, and is suitable for more general user non-uniform clustering scenes. In order to improve the energy efficiency of the IRS-NOMA network, the invention provides a joint optimization algorithm based on SDR to minimize the transmitting power. Simulation results show that the SDR algorithm has significant advantages when the requirement for the target rate is high.

The invention provides a design method of a power domain NOMA secure communication system assisted by an intelligent reflecting surface, which comprises two scenes of external eavesdropping and internal eavesdropping, and comprises the following steps of: sending information to legal non-orthogonal users by a base station through the assistance of the intelligent reflecting surface; establishing an intelligent reflector-assisted NOMA secure communication system model, giving a received signal expression and a detection signal-to-noise ratio of a legal user and an eavesdropping user, converting continuous phase shift of a reflection unit into random phase shift by using a 1-bit coding mechanism, performing on-off control on the reflection unit through 1 and 0, maximizing the reception signal-to-interference-and-noise-ratio of the legal user, inhibiting the performance of an eavesdropper, deriving a theoretical expression of the security outage probability of the non-orthogonal user. Compared with an intelligent reflecting surface assisted OMA system, the method has the advantages that the safety outage probability performance is improved, and the good application value is achieved.

Method to perform joint scheduling in the downlink or in the uplink of a centralized OFDM radio access network for a plurality of users considering time, frequency and space domains, scheduler device thereof and computer program products.The method to be applied in the downlink or in the uplink of a centralized radio access network based on OFDM, whereby a set of remote radio heads of a set of remote units are connected to a central unit, that performs all (or part of) the radio-related processing tasks, wherein the scheduling exploit CoMP, NOMA and RF conditions and resource blanking techniques.

The invention belongs to the field of wireless physical layers, discloses a wireless energy-carrying NOMA cooperative network power optimization method, and mainly solves the problem of insufficient energy supply of secondary user nodes in an existing NOMA cooperative cognitive radio network. The implementation scheme comprises the following steps: firstly, constructing a NOMA (Non-Orthogonal Multiple Access) cooperative network model based on a radio frequency energy collection technology, and simultaneously receiving signals and radio frequency energy at a secondary user receiver by adoptinga power division architecture; a. An improved genetic algorithm is designed to optimize the power distribution factor and the time slot distribution factor of the model so as to maximize the throughput of the secondary user system. According to the invention, the optimal power distribution factor and time slot distribution factor are obtained, the improvement of the system spectrum efficiency andthe improvement of the energy efficiency of the secondary user system are realized, the service life of the secondary user node is prolonged, and the transmission performance of the whole system is improved.

The invention relates to a millimeter wave MIMO-NOMA method of a downlink broadcast link based on beam aggregation, and belongs to the field of communication. In order to solve the problems of user pairing and beam accurate alignment in a downlink broadcast link in the prior art, the invention provides a millimeter wave large-scale MIMO-NOMA method based on beam aggregation. According to the invention, the device is provided, the base station generates a large-scale beam set covering the whole cell through beam forming; wherein a plurality of adjacent beams are gathered together to provide services for a group of adjacent users in a non-orthogonal mode, and an approximately optimal digital precoding matrix is designed according to channel state information by constructing a deep learning architecture and adopting an offline training online application mode, so that interference among the users is reduced, and fairness of users' households is realized. According to the invention, strictbeam alignment between users is not required, and the possibility of NOMA scheme application in downlink millimeter wave MIMO can be increased.

The invention provides a resource allocation method and device based on NOMA (Non-Orthogonal Multiple Access). The method comprises the following steps: an uplink non-orthogonal multiple access millimeter wave system model in which a base station adopts a fully-connected sparse radio frequency link antenna structure is established; an analog beam design based on a codebook and an improved NOMA decoding scheme are provided; a maximum and minimum user energy efficiency (EE) optimization problem is constructed by jointly optimizing the detection matrix at the BS and the sending power at the user;a fractional objective function is converted into a subtractive objective function, a double-loop iterative algorithm is provided to solve the fractional objective function, a detection matrix and transmitting power are iteratively updated in an inner loop, and the optimal solution of the problem is obtained in an outer loop by adopting double-section iteration. According to the uplink MIMO-NOMAmillimeter wave system researched by the invention, a codebook-based analog beam design is provided, so that the pilot overhead of channel estimation is reduced; the joint optimization design of the transmitting power of the user and the detection matrix of the BS achieves better performance in the aspects of spectral efficiency and energy efficiency.

A method for performing, by a terminal, a contention-based uplink transmission in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: selecting any one of a plurality of codewords and any one of a plurality of demodulation reference signals (DMRS), the plurality of codewords and the plurality of DMRSs being set in a contention resource area for a contention-based uplink transmission; and transmitting, through the contention resource area, uplink data that corresponds to the selected codeword, and the selected DMRS, wherein the DMRS is transmitted in an orthogonal multiple access (OMA) scheme, the uplink data is transmitted in a non-orthogonal multiple access (NOMA) scheme, and the selected DMRS is one of the K DMRSs mapped to the selected codeword, wherein K may be an integer greater than or equal to 1, which is changed according to a DMRS collision occurring in the contention resource area.

The invention discloses a mobile edge computing network task high-safety unloading resource allocation method based on NOMA. Under the conditions that the channel state information of an eavesdropperis not completely known and the safety rate and the transmission power are limited, information is safely unloaded by maximizing the minimum anti-eavesdropping capability of the uplink NOMA user. Twousers simultaneously unload respective partial tasks to an access point equipped with a mobile edge computing server at the periphery in a resource block sharing manner through a NOMA uplink so as tocarry out rapid processing; a positive auxiliary role in the mobile user computing task is realized, and it is ensured that the mobile user side quickly executes the computing task with low delay tolerance and high complexity. The method has the advantage that under the condition that the actual eavesdropper channel state information is not completely known, safe unloading of the information is ensured by enhancing the anti-eavesdropping capability. The invention also defines an interrupt event based on probability analysis so as to measure the communication performance of the system and evaluate influence of the sending power and the unloading task load on the system performance.

The invention discloses a power distribution method in a downlink NOMA system of a depth deterministic strategy gradient algorithm, and the method employs a double neural network structure and an experience pool playback mechanism, can effectively solve a problem related to a large-scale state action space, reduces the correlation between training samples, employs a deterministic strategy to select an action, and an action may be selected in a continuous action space. According to the algorithm, state information is used as input of a neural network, a state space, an action space and a rewardfunction are correspondingly designed according to a simulation downlink NOMA system situation, and signal to interference plus noise ratio information and rate information at the last moment are used as components of the state information at the current moment. According to the invention, the intelligent agent can learn and utilize the learned information to improve the behavior strategy more effectively, and an optimal power distribution strategy is obtained after multiple iterations. The method can effectively solve the problem of power distribution of multiple users in the downlink NOMA system, has good generalization performance under different user numbers and the transmitting power level of the base station, can effectively improve the rationality of power distribution, consumes less operation time, and effectively improves the efficiency of power distribution.

The invention discloses an algorithm for solving power distribution in cognitive radio based on reinforcement learning, which comprises the following steps: S1, setting initial value parameters of a deep learning algorithm, S2, setting a scene model related to a CR-NOMA system, and setting an initial state set related to states and actions; S3, when a certain calculation moment t is smaller than or equal to the time value Tmax of the maximum limit, solving a state value at the moment t, calculating a corresponding reward function, and calculating a TD error [delta]t; S4, selecting the next action of the user based on the value function, and updating the initial value function to Q (st, at)<-Q(st, at)+[eta]c[delta]t by using the learning rate and the TD error value function; obtaining a corresponding reward according to the selected execution action, obtaining a strategy function [pi](g), and updating the strategy function [pi](g) to [pi](st, at)<-[pi](st, at)-[eta]a[delta]t; [pi](g); and S5, enabling the TD error value to reach the minimum according to the step S3, continuously iteratively updating, and finally obtaining the maximum reward function value, i.e., ending the allocation algorithm. The problem that in the prior art, power distribution cannot be well conducted on the premise that channel information is incomplete is solved.

The invention discloses a downlink transmission time delay minimization method based on an NOMA-MEC system, and the method comprises the steps: firstly building a system model of a base station with amobile edge computing server and K mobile users, and enabling the base station and the users to be provided with a single antenna for transmitting and receiving signals; deducing a signal-to-noise ratio, a transmission bit constraint, a power constraint and an energy consumption constraint of the user according to the transmission characteristics of the downlink NOMA and the characteristics of the MEC system; then, a mathematical model with the purpose of minimizing system time delay is constructed; and finally, designing an optimization algorithm to obtain an optimal resource allocation scheme with the purpose of minimizing the time delay. According to the method, the problem that the time delay and the energy efficiency of an existing NOMA-MEC system are unbalanced in the downlink transmission process in a multi-user scene is solved, and the transmission time delay of the system can be reduced to the minimum under the common constraint of the calculation task, the power and the energy consumption.

The invention discloses an uplink NOMA resource allocation method based on deep reinforcement learning. According to the method, under the condition that the minimum transmission rate of each user ismet, the energy efficiency of the whole system is improved by selecting the optimal sub-channel allocation strategy and power allocation strategy, and the power consumed by transmission is effectivelyreduced. The method is based on a deep Q network in deep reinforcement learning, network parameters are adjusted according to feedback of an NOMA system, and optimal sub-channel and power distribution is achieved. According to the method, the deep Q network is adapted to the continuous resource allocation task through power discretization, and the output dimension of the network is reduced by using a distributed network structure, so that the performance of the whole resource allocation network is improved. Compared with other methods, the method has the advantages that better average overallenergy efficiency can be obtained, and good performance can be obtained under the condition of different transmission power limits.

The invention discloses a downlink NOMA power distribution method in a multi-beam LEO satellite communication system. The power distribution method comprises the steps: firstly constructing the downlink sum rate of a multi-beam LEO satellite, determining the rate of a kth user in a beam i and whether the jth resource of an ith beam is distributed to the kth user of the beam or not under the constraint conditions, and determining whether the jth resource of the ith beam is distributed to the kth user, wherein the i represents the jth resource of the ith wave beam to be allocated to the kth userof the wave beam and represents the jth resource of the ith wave beam not to be allocated to the kth user of the wave beam, the Pmax represents the total downlink power of the satellite and the powerof the kth user in the wave beam i, and the Rmin represents the minimum receiving rate requirement of the user; solving the maximum power distribution scheme of f (P) through a genetic algorithm; andfinally, configuring power values of all users in the multi-beam LEO satellite communication system according to the obtained power allocation scheme, and meanwhile, accessing the users to corresponding regions and allocating corresponding time-frequency resources. According to the invention, the downlink sum rate and the spectrum utilization rate of the system can be improved, so that the systemobtains the maximum throughput.

The invention discloses an RIS-assisted NOMA enabled VLC / RF hybrid network secure transmission method, which is characterized in that an optical access point is configured at the indoor top, and a relay node is arranged on a desktop right below the optical access point; the optical wave beam of the optical access point can cover the edge of the round table top furthest, so that the NOMA user on the ground cannot directly receive the signal sent by the optical access point, and then the relay node is utilized to relay and transmit the electric signal to a reconfigurable intelligent surface (RIS) after photoelectric conversion; then the RIS reflects the signal to the NOMA user, and the eavesdropping node eavesdrops the information of the user in the process; on the basis of analyzing channelstatistical characteristics of an optical wireless link and a radio frequency wireless link, the safety outage probability and strict positive safety capacity of the VLC / RF hybrid network during amplification forwarding and decoding forwarding transmission are obtained respectively. Simulation verifies that the performance of the secure transmission method provided by the invention is related tothe number of reflection element surfaces, indoor layout, optical access point characteristics and radio frequency transmission characteristics.

The invention discloses an opportunistic cooperative multicast method. The method comprises the following steps that: a base station recodes, modulates and forwards unicast user information obtained by decoding as an optimal multicast user according to the worst forwarding link channel gain of each selected multicast user and each unicast user if the multicast user judges that the worst forwardinglink channel gain with all the unicast users is the highest. According to the invention, the link state from a multicast user to a unicast user is considered in the collaborative multicast method; nomatter for one or more unicast users, the performance of the unicast users can be guaranteed under the condition that the link gain from the multicast users to the unicast users is poor.

A method for transmitting and receiving data using a non-orthogonal multiple access (NOMA) in a wireless communication system, the method performed by a first user equipment (UE) includes receiving first downlink control information (DCI) including information related to physical downlink shared channel (PDSCH) scheduling of the first UE from a base station, receiving second DCI including information related to PDSCH cancellation of a second UE from the base station, receiving a superposition signal from the base station through a specific resource, and decoding the PDSCH of the first UE by cancelling the PDSCH of the second UE from the superposition signal based on the received second DCI.

The invention discloses a user matching and power distribution method of an MIMO-NOMA downlink communication system. The user matching method comprises the following steps: dividing all users into a strong user group and a weak user group according to a channel gain sorting result, sequentially selecting the users of the strong user group, calculating the correlation coefficients between the usersand each user of the weak user group, selecting the weak user with the highest correlation coefficient as the weak user of the cluster where the strong user is located, and respectively excluding thematched users from the respective user groups; and completing until matching of all strong users and weak users. According to the user allocation method provided by the invention, the inter-cluster interference on weak users in the cluster in a scene with relatively low inter-user channel relevancy is less than that of a traditional MIMO-NOMA scheme, so that the total throughput of a communication system is improved; the power distribution method provided by the invention has relatively low calculation complexity, and ensures the lowest rate of the users in the cluster while maximizing the total throughput of the communication system.

The invention relates to a robust resource allocation method for an NOMA and energy-carrying D2D fusion network, and belongs to the technical field of communication. The method comprises the followingsteps: constructing an NOMA and energy-carrying D2D fusion network; wherein the cellular users adopt downlink NOMA (Non-Orthogonal Multiple Access) transmission, so that a plurality of users can reuse the same resource block; d2D users are provided with energy collection circuits, and a substrate type frequency spectrum access mode is adopted; considering a random channel uncertainty model, and establishing a resource allocation optimization problem by taking the maximum total energy efficiency of the system as a target function; jointly optimizing the power splitting ratio, the resource block allocation factor and the transmitting power, so the energy efficiency of the system is maximized while the communication quality of the cellular users is ensured. Experimental results show that themethod has high system energy efficiency and good robustness.

The invention discloses a multi-user detection method of a non-orthogonal multiple access system based on compressed sensing. The method can be applied to an unlicensed NOMA uplink transmission system. According to the method, a generalized Dice coefficient matching criterion is used for replacing a traditional inner product matching criterion; multi-user detection can be realized without knowingthe number of active users of the system; the accuracy of the selected user support set is improved; therefore, the accuracy of multi-user detection is improved. Besides, an iteration termination threshold value based on noise energy is set; iteration of the algorithm is effectively terminated in time, under-estimation and over-estimation of the number of active users are avoided, finally, a variable step size mechanism with large step size rapid approaching and small step size accurate approaching is introduced, the multi-user detection rate is increased, and the users can be rapidly and accurately detected in an unlicensed NOMA uplink transmission system.

A mechanism for attributing users to a plurality of sub bands in a time slot t in a multiple access communications system, said method comprising assigning a combination of users to a sub band on a Proportional Fairness basis, that is to say whichever combination of users maximizes a Proportional Fairness performance metric for that channel, where the performance metric is weighted by a weighting factor reflecting the difference for that user between a target throughput and a projected throughput.

The invention discloses a safety energy efficiency maximization power distribution method for a millimeter wave NOMA system based on SWIPT, which is used for combining wireless energy-carrying communication with a millimeter wave large-scale MIMO-NOMA system based on hybrid precoding and analyzing a safety energy efficiency maximization power distribution problem when an eavesdropper exists in the system. The hybrid precoding is composed of digital precoding and analog precoding, an optimization problem with maximized safety energy efficiency is formed by combining SWIPT on this basis, and meanwhile, the total power limitation of legal users, the constraints of the user rate QoS and the collected energy QoS and the channel uncertainty of eavesdroppers are considered. Compared with a traditional digital coding system, the power distribution scheme provided by the invention is better in safety and energy efficiency.