Double-hop cooperative transporting method based on physical-layer network coding

Abstract

The invention provides a double-hop cooperative transporting method based on physical-layer network coding, which comprises the following steps of: each MS adds a CPI with a proper length on an OFDM signal to be transmitted when each MS transmits a first transmission signal to a selected RS, and respectively and simultaneously transmits to the RS; and the RS firstly eliminates the CP1 from the received multi-channel OPDM signal to remove a first time error existed in the system, emerges with a PNC, adds the CP2 with the proper length on the emerged signal when the RS transmits a second signalto a BS, and transmits the signal to the BS so as to help the MS to transmit the information. The BS delimitates the CP2 from the received and emerged signal to remove a second time error existed in the system, and indirectly obtains the required information by means of PNC decoding. Therefore, even if the uplink from one MS to the BS is interrupted, the BS also can obtain the transmitted information, so that the method improves the network transmission quality.

Description

technical field [0001] The invention relates to the technical field of wireless transmission based on network coding and IEEE 802.16j standard, in particular to a two-hop cooperative transmission method based on physical layer network coding. Background technique [0002] In order to achieve the goals of high data rate, high spectrum efficiency and seamless coverage of future wireless communication systems, IEEE 802.16j mobile multi-hop relay standard introduces RS (Relay Station, relay station) in the network to strengthen WiMax (Worldwide Interoperability for Microwave Access, Global Microwave Interconnection Access) system performance. When the mobile terminal cannot use multiple antennas, relay cooperation can be used as a way to achieve space diversity to improve system performance. [0003] In traditional relay cooperation, no signal collision is allowed at the RS, and the RS can only simply forward the received signal, so the spectrum efficiency is low. PNC (physica...

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Problems solved by technology

However, the previous studies on PNC all assume that the ideal channel has strict time synchronization, but in the actual environment, the channel has obvious frequency selective fading, and due to the distribution of nodes and the path delay of the multipath channel, the system is still There is a time error, and the above-mentioned channel fading and time error will lead to obvious system performance degradation and reduce the quality of network transmission

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