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

OFDM signal transmission method and device

A technology for signal transmission and signal reception, which is applied in the field of high-energy-efficiency signal transmission methods and devices, and can solve problems such as system energy efficiency degradation

Inactive Publication Date: 2014-04-16
SOUTHEAST UNIV
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, since the CP does not carry any useful information, inserting the CP will bring about a decrease in system energy efficiency

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
  • OFDM signal transmission method and device
  • OFDM signal transmission method and device
  • OFDM signal transmission method and device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0044] The present invention will be further described below in conjunction with the accompanying drawings.

[0045] Such as figure 1 As shown, a kind of OFDM signal transmission method that the present invention provides, at first calculates the power reduction factor according to the delay power spectrum of multipath channel and the signal-to-noise ratio of the received signal at the receiving end, then feeds back the power factor to the sending end, and Multiplying each sampling point in the cyclic prefix CP at the sending end reduces the average power of the cyclic prefix, thereby improving the energy efficiency of the transmitted signal. Specific steps are as follows:

[0046] (1) Estimate the delay power spectrum of the channel and the signal-to-noise ratio of the received signal

[0047] Suppose an OFDM system contains N subcarriers, and the length of the cyclic prefix CP is G. The receiving end of the OFDM system performs N-point discrete Fourier transform (DFT) on t...

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 discloses an OFDM signal transmission method which comprises the following steps that (1) a receiving end estimates the delay power spectrum of a channel and the signal to noise ratio of received signals, a power reduction factor alpha is computed according to the delay power spectrum and the signal to noise ratio of the received signals, and then the power reduction factor alpha is fed back to a sending end; (2) the sending end enables sampling points in cyclic prefixes (CP) of OFDM symbols to be transmitted to be multiplied by the received power reduction factor alpha, and then the sampling points are formed in a filtering-modulation mode to carrier frequency to be transmitted; and the invention further provides a device for implementing the method. Under the premise that system receiving performance is basically kept unchanged, the power of the CP is lowered, the energy efficiency of transmitted signals is improved, quickness and reliability are achieved, and implementation complexity is low. The method and device are suitable for an OFDM system and other mobile communication systems with the CP.

Description

technical field [0001] The invention relates to the field of green energy saving in a mobile communication system, in particular to an energy-efficient signal transmission method and device applied to an Orthogonal Frequency Division Multiplexing (OFDM) system. Background technique [0002] At present, OFDM has become the mainstream air interface technology of the fourth generation (4G) mobile communication system. The 4G system adopts DFT-s-OFDM and OFDMA technologies in the uplink and downlink respectively. In an OFDM system, in order to eliminate inter-symbol interference (ISI), a cyclic prefix (CP) must be inserted in front of each OFDM symbol. CP is the copy of the tail of the symbol. It is usually greater than the maximum delay spread caused by the multipath fading channel, and at the same time, the linear convolution of the transmitted signal and the multipath channel is changed into a circular convolution. However, since the CP does not carry any useful informatio...

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
IPC IPC(8): H04L27/26
Inventor 盛彬严岩李夏刘磊
Owner SOUTHEAST UNIV