Carrier interferometry orthogonal frequency division multiplexing (CI-OFDM) communication method based on consideration of inter-carrier interference (ICI) influences under time-varying fading channels

Abstract

The invention provides a carrier interferometry orthogonal frequency division multiplexing (CI-OFDM) communication method based on consideration of inter-carrier interference (ICI) influences under time-varying fading channels, belonging to the technical field of communications. The method comprises the steps as follows: a sender sequentially carries out digital modulation and carrier interference code extension on information source data, then transforms symbols of the extended data to time domains by inverse discrete Fourier transform (IDFT) at an N point, and finally performs OFDM transmission after cyclic prefixes are added; after a receiver receives the data, the receiver gets rid of the cyclic prefixes, and transforms symbols of the received data to frequency domains by discrete Fourier transform (DFT) at the N point; the received OFDM signals are detected, and the influences caused by the ICI are considered in the detection so as to obtain estimated values of data symbols whichare subjected to the digital modulation; and carrier interference code de-extension and the digital modulation are sequentially carried out on the modulated data symbols by the DFT at the N point so as to obtain information sink bit data. In the method, because the ICI influences are considered in the signal detection, and combined noises and the data symbols are taken as receiving signals, thus the minimum mean square error (MMSE) equilibrium can be performed more accurately. Compared with a traditional OFDM communication method, the method provided by the invention has the advantages of thegrains produced by frequency multipath diversity and the improvement of error rate performance gains and channel estimation accuracy due to reduction of the ICI.

Description

technical field [0001] The invention belongs to the technical field of communication, and relates to a communication method considering inter-carrier interference (Inter-Carrier Interference, ICI) and carrier interference OFDM (Carrier Interferometry Orthogonal Frequency Division Multiplexing, CI-OFDM). Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) has been widely used in various WLANs, new generation cellular mobile communication systems, digital broadcasting and TV, etc. in high-speed data transmission systems. [0003] The main reason why OFDM can become the core technology of various mainstream standards is that it can convert frequency-selective fading channels into parallel flat-fading sub-channels by rationally designing system parameters, thus effectively combating inter-symbol interference (Inter-symbol interference). Symbol Interference, ISI) at the same time, reduce the complexity of equalization processing at the receiving end. ...

AI Technical Summary

Problems solved by technology

However, under the time-varying fading channel of CI-OFDM, due to the existence of Doppler frequency shift, there will be Inter-Carrier Interference (ICI), which will affect the performance of data symbol detection

[0005] The traditional CI-OFDM system does not consider the communication in the time-varying fading channel, the impact of CI-OFDM and traditional OFDM due to the difference in ICI

Images