Transmission method combined with network coding and channel decoding based on adaptive modulation

Abstract

The invention provides a transmission method combined with network coding and channel decoding based on adaptive modulation, which adaptively adjusts the modulation mode according to the actual channel condition and can improve the channel capacity as far as possible while maintaining lower bit error rate performance. The method comprises the following steps: two moving source nodes respectively carry out linear coding and modulation on the packets to be transmitted and the modulation mode is adaptively adjusted according to the channel condition; then the modulating signals are transmitted to a relay node; the relay node carries out modulating signal recognition on the received information from the two source nodes respectively and carries out corresponding soft demodulation according to the modulation mode information; after obtaining two-way demodulated soft decision information, the relay node carries out network coding, namely consolidating soft information, the consolidated soft information undergoes channel decoding to obtain target packets, and the relay node transmits the target packets by broadcasting; and the two source nodes receive the packets broadcast by the relay node and carry out decoding by virtue of the existing information, thus obtaining the opposite node information and completing information exchange.

Description

technical field [0001] The invention relates to the technical field of wireless transmission based on network coding and channel decoding. Background technique [0002] Network coding essentially breaks the traditional information processing methods in communication networks, and it has become a new research hotspot in the field of communication network research. The network coding mechanism allows the relay node to encode and forward the information received from multiple paths, and the receiving node decodes accordingly to obtain the original information. The bottleneck problem shows its superiority in improving network throughput, improving load balancing, reducing transmission delay, saving node energy consumption, and enhancing network robustness. The early research of network coding was limited to multicast transmission of wired network. Due to the broadcast characteristics of wireless network itself, or the advantage of wireless multicast, the application of network ...

AI Technical Summary

Problems solved by technology

[0003] However, due to the time-varying fading characteristics of the mobile communication channel, the wireless signal will be affected by the multipath effect and cause serious amplitude fading and delay expansion, resulting in the deterioration of the bit error rate performance.

One way to overcome the amplitude fading is to increase the transmit power and increase the amplitude margin; another way is to reduce the bit transmission rate in the wireless channel, and the reduction of the bit transmission rate will reduce the spectrum utilization, that is, reduce the system capacity

In addition, because the link budget of the non-adaptive system must meet the worst case of channel quality, when the channel quality is good, the system cannot make full use of the channel capacity, resulting in a waste of spectrum resources; and future mobile communications need to develop high-speed data transmission business

[0004] Therefore, in the prior art, there is no perfect wireless transmission scheme that achieves better performance in both system capacity and system bit error performance under the condition of constantly changing channel state

Images