Cognitive user access method and system in cognitive relay network based on mixed NOMA

Abstract

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.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a cognitive user access method and system in a hybrid NOMA-based cognitive relay network. Background technique [0002] Currently, the closest prior art: Current research on cognitive cooperative NOMA mainly focuses on the assumption that there is no direct link between the primary user transceivers, while the cognitive user transceivers have direct links, and the cognitive user transmitters By using the form of NOMA to forward the signal to the primary user, and at the same time send the signal to the receiver of the cognitive user, or assuming that there is a direct transmission link between the primary user's transceiver and the transmitter, and there is no direct transmission link between the cognitive user's transceiver, through Signals are forwarded to cognitive user receivers by means of relay nodes. However, in actual communication, there is a ...

AI Technical Summary

Problems solved by technology

[0003] To sum up, the problems existing in the existing technology are: in actual communication scenarios, due to factors such as path loss, there is no direct transmission link between the main user transceivers, and there is no direct link between the cognitive user transceivers. For the transmission link, it is necessary to use relay nodes for forwarding. For this scenario, there is currently no method for cognitive users to access the authorized frequency band of the main user.

For this scenario, using traditional cognitive radio technology, cognitive users cannot access, because if the cognitive user adopts the Underlay mode, the main user transmitter and the cognitive user transmitter send the relay node at the same time signal, the relay node can only decode one of the signals and treat the other signal as noise. Since the priority of the primary user is high, the relay node chooses to decode the signal of the primary user, and the cognitive user has no access opportunity

When a cognitive user uses the Overlay mode to access, the primary user must not use its licensed frequency band in certain time slots. When the primary user has been using its licensed frequency band, the cognitive user cannot access it in the Overlay mode.

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