36 results about "Half duplex relay" patented technology

The invention concerns a method to allocate transmission resources in a cell network of cooperative type. Each cell comprises a source, a receiver and optionally a half-duplex relay to relay data transmitted by the source to the receiver. The invention draws advantage from the half-duplex mode of a relay belonging to a cell, by allocating to the source of a neighbouring cell a resource used by this relay during one same transmission timeslot.

In one aspect of the invention, a method for transmission in a wireless communication system includes selecting by a signal destination one of a source-destination direct transmission, a decode-forward relay transmission, and a compress-forward transmission, responsive to channel gains between a signal source and a relay, between the signal source and the signal destination, and between the relay and the signal destination; informing a selected transmission mode from the selecting step to the signal source and the relay; and operating in the selected transmission mode by the relay.

The invention relates to a method (1) for transmitting a digital signal to a network with at least four nodes comprising two transmitters, a relay and a receiver, separated from one another by non-orthogonal links using a spatially distributed network code. The method includes the following steps: a step (2) in each transmitter, delivering a code word comprising first and second redundancy parts per block of K data bits, whereby the first part can be decoded independently of the second part; a step (3) comprising the transmission in the transmitters of the first part of the code word over aN, a is an element of a set [0,1] transmission intervals; a step (4) comprising combined iterative detection / decoding in the relay, in order to separate the flux originating from the transmitters and to determine, for each flux, a vector representative of the K data bits associated with the code word; a step (5) comprising the combined encoding in the relay of the two vectors in order to determine a redundancy datum; providing an order in the transmitters in order to transmit the second redundancy part over (1 - a )N, a is an element of a set [0, 1] subsequent transmission intervals; and providing an order in the relay in order to transmit (6) the redundancy datum over the (1 - a)N, a is an element of a set [0,1] subsequent transmission intervals.

A relaying method performed by a half duplex relay for a telecommunications system. The method includes a reception stage of receiving codewords transmitted by a source, the successive codewords corresponding to B blocks, the first of which can be decoded independently of the other blocks. This stage includes a decoding step of estimating a message from each source based on received codewords, the message being associated with the codewords transmitted by the source. The relay performs an error detection and decision-taking step on messages that are decoded without error. The relay encodes a signal and forwards it to the destination, wherein the signal is representative of only those messages that are decoded without error, such that the relay passes from non-selective reception to selective reception after receiving B1 blocks and switches from the reception stage to the encoding and forwarding stage under control of the error detection and decision stage.

A method and device are provided for transmitting a digital signal intended for a network having at least four nodes including two transmitters, a relay and a receiver separated from one another by non-orthogonal links, except between the relay and the destination, between which the link is orthogonal, implementing a spatially distributed network code. The method includes: encoding, in each transmitter, supplying a code word for every block of K bits of information; transmitting, in the transmitters, the code word during αN transmission intervals, αε[0,1]; jointly, iteratively detecting / decoding, in the relay, in order to separate interfering streams from the transmitters and to determine, for each stream, a vector representing the K bits of information associated with the code word; jointly encoding, in the relay, the two vectors in order to determine redundancy information, and scheduling the relays to transmit the redundancy information during the (1−α)N following transmission intervals.

In one aspect of the invention, a method for transmission in a wireless communication system includes selecting by a signal destination one of a source-destination direct transmission, a decode-forward relay transmission, and a compress-forward transmission, responsive to channel gains between a signal source and a relay, between the signal source and the signal destination, and between the relay and the signal destination; informing a selected transmission mode from the selecting step to the signal source and the relay; and operating in the selected transmission mode by the relay.

A relaying method performed by a half duplex relay for a telecommunications system. The method includes a reception stage of receiving codewords transmitted by a source, the successive codewords corresponding to B blocks, the first of which can be decoded independently of the other blocks. This stage includes a decoding step of estimating a message from each source based on received codewords, the message being associated with the codewords transmitted by the source. The relay performs an error detection and decision-taking step on messages that are decoded without error. The relay encodes a signal and forwards it to the destination, wherein the signal is representative of only those messages that are decoded without error, such that the relay passes from non-selective reception to selective reception after receiving B1 blocks and switches from the reception stage to the encoding and forwarding stage under control of the error detection and decision stage.

A relaying method in a telecommunication system having a plurality of sources, a half-duplex relay relay and a recipient. The relay performs a receiving phase of: receiving codewords transmitted by the sources, including estimating for each source a message associated with the codewords transmitted by the source, error detection and decision of error-free decoded messages, which determine the set of sources decoded without error by the relay; a phase of coding and transmitting to the recipient a signal uniquely representative of the selection of messages, such that, after each reception of a block from different sources, the relay receives and decodes a return path from the destination indicating if no or at least one message is decoded without error, these messages determining the set of sources decoded without error. The relay switches from the receiving phase to the coding and transmission phase once a logic rule is valid.

The invention concerns a method to allocate transmission resources in a cell network of cooperative type. Each cell comprises a source, a receiver and optionally a half-duplex relay to relay data transmitted by the source to the receiver. The invention draws advantage from the half-duplex mode of a relay belonging to a cell, by allocating to the source of a neighbouring cell a resource used by this relay during one same transmission timeslot.

The invention relates to a method (1) of transmitting digital signals to a network having at least four nodes comprising two nodes separated from each other by non-orthogonal links using a spatially distributed network code. transmitters, relays, and receivers. The method comprises the following steps: a step (2) in each transmitter for delivering a codeword in blocks of K data bits, the codeword comprising a first and a second redundant part, thereby being compatible with the first The two parts independently decode the first part; step (3), including transmitting the first part of the codeword in the transmitter at αN,α∈[0,1] transmission intervals; step (4), including the combined iterative detection / decoding in the relay to separate the traffic originating from said transmitter and to determine for each traffic a vector representing the K data bits associated with the codeword; step (5) , including combinatorial encoding of the two vectors in the relay in order to determine redundant data; providing an order in the transmitter such that in (1-α)N,α∈[0,1] subsequent transmitting the second redundant portion on transmission intervals; and providing an order in the relay to transmit (6) the redundant data on (1-α)N,α∈[0,1] subsequent transmission intervals .

The invention discloses a virtual full-duplex relay transmission method based on a half-duplex multipath cooperative system, and belongs to the technical field of wireless cooperative communication. The virtual full-duplex relay transmission method based on the half-duplex multipath cooperative system includes the following steps: N relay nodes are added between an information source S and an information sink D to build multi-path relay channels, among all relay nodes capable of successfully decoding a source signal, a relay node with the best channel conditions is selected through a corresponding algorithm to forward the decoded signal, and at the same time, the information source generates a new signal, and transmits the signal to the rest of relay nodes. Thus, in each time slot, the information source can transmit a new signal without waiting for a signal of the last time slot to be relayed and forwarded, thereby realizing virtual all-duplex relay transmission. The virtual full-duplex relay transmission method makes a simulation analysis of interrupt performance, and compared with conventional multi-path relay channels, the method improves the spectrum efficiency of the multi-path relay channels while ensuring a diversity gain, thereby improving performance of a whole system.

The invention provides an optimal power distribution method in an untrusted relay network. A communication process of a two-hop half-duplex relay network is modelled at first; then, the system security capacity and the energy efficiency are comprehensively considered; on the premise that the total power is ensured to be constant, an optical power distribution factor is solved; therefore, the security energy efficiency of a system is maximum; and the security energy efficiency of the power limited two-hop half-duplex network is increased. According to the optical power distribution method disclosed by the invention, the energy efficiency is considered; the security energy efficiency can be maximized under a total power limiting condition; furthermore, user information is prevented from being cracked by an untrusted relay node as much as possible; a calculation process is simplified through a taylor expansion; and furthermore, the estimation error due to use of the first item in the expansion is not beyond 1%, and can be ignored.

A relaying method performed by a half-duplex relay for a telecommunications system includes a reception stage of receiving codewords from sources during N uses of the transmission channel. The successive codewords correspond to B blocks, the first of which can be decoded independently of the other blocks. This stage includes a decoding step of estimating a message from each source based on received codewords. The relay performs an error detection and decision-taking step on messages decoded without error. The relay performs a stage of encoding a signal and forwarding it to a destination. The signal is representative of only messages decoded without error and includes channel encoding by an incremental redundancy code to obtain a channel encoded codeword. The relay passes from non-selective reception to selective reception after receiving B1 blocks and switches from the reception stage to the encoding and forwarding stage under control of the decision step.

The invention discloses a power control method embedded into a D2D cellular network and based on a time domain half-duplex relay, and belongs to the technical field of wireless communications. The method relates to a base station B using a point-to-multipoint topological structure cellular network for transmitting, a cellular network receiving terminal C, a D2D transmitting terminal R used as a cellular communication relay and a D2D receiving terminal E; the D2D transmitting terminal is used as a cellular communication relay between the base station B and the receiving terminal C, cellular communication and D2D communication are subjected to combined power control, the full-duplex wireless relay technology is used for achieving orthogonal communication channel frequency spectrum multiplex of the cellular communication and the D2D communication, the minimum data throughout requirement of the cellular communication is met, meanwhile, the throughout of the D2D communication is maximized, hence, the overall performance of the system and the individual performance of users can be considered at the same time, and good balance can be achieved between the system layer and the user layer.

The invention provides an optimal power allocation method of an untrusted relay network under perfect CSI. The method comprises the following steps: firstly, describing a communication scheme of a two-hop half-duplex relay network, then providing an optimal power allocation scheme, and finally analyzing channel ESR to acquire a reachable safety rate. According to the optimal power allocation method provided by the invention, an optimal power allocation formula in a transmission process is provided to maximize the safety rate, and the ESR under high SNR is further analyzed for evaluating the reachable average safety rate. The approximate optimal power allocation can bring a higher safety rate than equal power allocation.