A solution to f-ofdm system isi based on ici self-deletion technology

Abstract

The invention discloses a method for solving the ISI of an f-OFDM system based on the ICI self-deletion technology. The method is as follows: an ICI self-deletion coding module is set between the subcarrier mapping module and the IFFT module of the transmitting end, and an ICI self-deletion decoding module is set between the subcarrier demapping module and the FFT module of the receiving end; the ICI self-deletion The encoding module is used to modulate each data symbol output by the subcarrier mapping module onto a group of adjacent L subcarriers with a set weight; the ICI self-erasing decoding module is used for the data output by the FFT module The data belonging to the same sub-carrier group are combined linearly according to the set weight, wherein the weight used in the combination is correspondingly the same as the weight used by the transmitting end. The invention effectively reduces the influence of ISI introduced by f-OFDM system filter.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a method and a system for solving the ISI of an f-OFDM system based on ICI self-deletion technology. Background technique [0002] From the 1970s to the present, wireless communication has developed from the first generation to the fourth generation. With the maturity of 4G technology and widespread commercial use, mobile communication has begun to move towards the development stage of 5G. The main driving force of 5G development is the mobile Internet and the Internet of Things. 5G will greatly improve performance on the basis of existing 4G system capabilities, and meet people's needs for high speed, ultra-high data capacity, massive number of connections, energy-saving communication, and ultimate user experience. wireless access requirements. [0003] At present, the LTE / LTE-A system uses CP-OFDM as the air interface technology, but it has the following dis...

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Problems solved by technology

[0003] At present, the LTE / LTE-A system uses CP-OFDM as the air interface technology, but it has the following disadvantages: only one fixed parameter configuration is supported on the entire system bandwidth, such as cyclic prefix (Cyclic Prefix, CP) length, subcarrier spacing , FFT points, etc.; rectangular pulse frequency response leads to large sidelobe leakage, requires more guard bandwidth, and low spectrum utilization; is sensitive to ISI and ICI (Inter-Carrier Interference, inter-carrier interference), and requires strict time and frequency synchronization. High system overhead, etc.

But at the same time, f-OFDM technology also has disadvantages: for example, f-OFDM divides the bandwidth of the system into different subbands, and the bandwidth of the subbands is not fixed. The system needs to design different filters for different subbands. Compared with the traditional OFDM system Only for filtering the entire frequency band, the complexity of the f-OFDM system is greatly increased; the filter length of the f-OFDM system is half a symbol length, which is greater than the length of the CP, and there is no additional guard interval, so f-OFDM symbols will be There is data overlap and interference, that is to say, the orthogonality of the time domain of the original OFDM symbol will be destroyed, and the inter-symbol interference (Inter-Symbol Interference, ISI) will be more serious

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