A method for device discovery in a base station-assisted d2d communication system

Abstract

The invention relates to the field of IMT-Advanced, in particular to a base station assisted method for discovering equipment in a D2D communication system. According to the base station assisted method for discovering the equipment in the D2D communication system, based on a request signaling sent to an eNB by UE requesting for being discovered, a resource block is distributed and reused by UE with location information capable of being obtained and UE with location information not capable of being obtained by means of different methods under the condition that resource reutilization and distribution is not needed and under the condition that resource reutilization and distribution is needed. The base station assisted method for discovering the equipment in the D2D communication system has the advantages that the resource reutilization degree is controlled reasonably, interference and collision are reduced, and sizable number of equipment can be discovered within a certain period of time.

Description

technical field [0001] The present invention particularly relates to a method for discovering equipment in a base station-assisted D2D communication system, which relates to the field of IMT-Advanced. Background technique [0002] In the future, the advanced International Mobile Telecommunications (International Moblie Telecommunications-Advanced, IMT-Advanced) will provide a bandwidth up to 100 MHz to achieve high-speed transmission. In order to meet the requirements of IMT-Advanced, many new wireless access technologies have been proposed. Among them, device-to-device (device-to-device, D2D) communication, as a promising technology, has attracted more and more attention. D2D communication is a technology that allows direct communication between terminals under the control of the system. It can increase the spectral efficiency of the cellular communication system, reduce the transmission power of the terminal, reduce the load of the cell base station, and reduce battery co...

AI Technical Summary

Problems solved by technology

[0008] First: For scenarios where the equipment is relatively sparse, the fixed time-frequency resources set in advance are wasted;

[0009] Second: For scenarios with dense devices, multiple devices may multiplex the same time-frequency resources for the fixed time-frequency resources set in advance. At this time, there will be collisions in sending signals, which will lead to the extension of the discovery process and the discovery process. The number of devices does not meet the system requirements

As a result, due to the offset of the clock crystal oscillator, the time slot shifts, and UE1 and UE3, which would not conflict originally, send signals in the same time slot, resulting in a conflict, so that the receiving user equipment cannot accurately receive the signals of the two user equipment

The reason for this situation is that the system uses a large number of continuous uplink time slots to send discovery signals, but the synchronization signal with the base station needs to be sent in downlink time slots, and the device cannot synchronize with the base station in time.

At the same time, such time-frequency resources of continuous time slots are not suitable for Time Division Duplex (TDD) systems

[0011] Fourth: The cycle of the existing discovery process is relatively long, the typical value is 8s, the device detects each resource block in the first 8s, and then determines the available resource blocks in the next 8s

However, for terminals moving at low and medium speeds, the change of the device's position after 8s has brought about changes in the topology of the wireless network, resulting in results obtained in the previous 8s that cannot be accurately used in the next 8s.

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