Unlock instant, AI-driven research and patent intelligence for your innovation.

Subcarrier index differential modulation method for OFDM (Orthogonal Frequency Division Multiplexing) system

A differential modulation and subcarrier technology, applied in the field of differential subcarrier index modulation and differential space modulation, can solve the problems of channel estimation performance impact and other issues

Inactive Publication Date: 2018-10-02
UNIV OF ELECTRONICS SCI & TECH OF CHINA
View PDF5 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that due to the block method, the SIM-OFDM system cannot simply insert pilots at fixed positions to complete channel estimation like in the OFDM system.
The wrong judgment of the pilot position will have a huge impact on the channel estimation performance of the SIM-OFDM system.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Subcarrier index differential modulation method for OFDM (Orthogonal Frequency Division Multiplexing) system
  • Subcarrier index differential modulation method for OFDM (Orthogonal Frequency Division Multiplexing) system
  • Subcarrier index differential modulation method for OFDM (Orthogonal Frequency Division Multiplexing) system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0023] Below in conjunction with accompanying drawing and embodiment, describe technical solution of the present invention in detail:

[0024] Taking G=4 and BPSK modulation as an example, then Q=4. Then the bits transmitted by each subcarrier block are log 2 Q+log 2 L=3bit.

[0025] Step 1: Get the reference symbols transmitted by the first 4 sub-blocks, That is, matrix E.

[0026] Step 2: Obtain the set of RDSM transmission vectors with length G: a 1 =[1 0 0 0] T , a 2 =[0 1 0 0] T , a 3 =[0 0 1 0] T , a 4 =[0 0 0 1] T . Assume that the bits transmitted by the i=5th sub-block are Transmission bits are divided into B 1 = log 2 Q=2 and B 2 = log 2 M=1 two parts.

[0027] Step 3: Front B 1 = 2 bits Used to select the transmit antenna vector After B 2 = 1 bit (0) is modulated by BPSK to +1, ie s 1 (5) = +1. get

[0028] Step 4: Since but The transmission vector of the i=5th sub-block obtained by differential encoding is:

[0029]

[0030]...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention belongs to the technical field of wireless communication and particularly relates to a differential subcarrier index modulation method for an OFDM (Orthogonal Frequency Division Multiplexing) system. In the scheme, bit information is together transmitted through a subcarrier index and a PSK symbol, differential modulation is carried out on the subcarrier index at the same time, and no channel information is needed in the case of detection. As is seen from a simulation result, the performance of the mentioned D-IM-OFDM (Differential index modulation OFDM) system is better than that of the traditional D-OFDM system, about 1.5dB performance losses are caused in comparison with SIM (Subcarrier Index Modulation)-OFDM, and the PAPR of the D-IM-OFDM system is lower than those of theOFDM system and the SIM-OFDM system. In a condition of keeping the performance advantages of the SIM-OFDM, the scheme has the advantage that DSM (Differential Spatial Modulation) detection does not need the channel information.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a differential subcarrier index modulation method for an OFDM system; the invention relates to differential spatial modulation (Differential spatial modulation, DSM), and OFDM (Multiple Input Multiple Output, MIMO), etc. technology. Background technique [0002] OFDM (Orthogonal Frequency Division Multiplexing) technology is a high-speed transmission technology for wireless communication. Its basic principle is to decompose the high-speed data stream into many low-rate sub-data streams, that is, divide the signal into many orthogonal sub-carriers, and use these mutual Orthogonal subcarriers are transmitted simultaneously. This technology uses subcarriers to modulate data, expands the pulse width of symbols, can effectively resist inter-symbol interference (Inter-Symbol Interference, ISI), and improves the performance against multipath fading. Compared...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L27/34H04L1/06
CPCH04L1/0612H04L1/0668H04L27/2637H04L27/3483
Inventor 吴朝武肖悦王金福肖丽霞
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA