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

LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method

A technology of sampling frequency offset and residual frequency offset, applied in multi-carrier systems, multi-frequency code systems, baseband system components, etc., can solve problems such as long coherence time, solve the impact of frequency offset, and reduce implementation complexity degree, the effect of avoiding interference and influence

Inactive Publication Date: 2014-02-26
CHONGQING TELECOMMUNICATION INSTITUTE
View PDF2 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In fact, for indoor and outdoor walking and low-to-medium speed moving scenes, due to the small Doppler frequency shift, it will have a longer coherence time

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
  • LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method
  • LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method
  • LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] This embodiment discloses the joint estimation of sampling frequency offset and carrier residual frequency offset based on the least squares algorithm, including the following steps:

[0022] 1) According to the comb-shaped pilot symbols at the transmitting end of the OFDM system, the corresponding actual comb-shaped pilot symbols at the receiving end, and the channel transfer function obtained by frequency-domain channel estimation, calculate the sampling frequency offset and carrier residual frequency offset. Amount of phase rotation. In this embodiment, the phase rotation model can be established by using the comb pilot in the OFDM system in, Indicates the actual received comb-shaped pilot symbol on the i-th comb-shaped pilot subcarrier in the l-th OFDM symbol at the receiving end, and the i-th comb-shaped pilot sub-carrier corresponds to the k-th comb-shaped pilot subcarrier in the OFDM system i subcarriers, Indicates the channel transfer function obtained by ...

Embodiment 2

[0027] This embodiment adopts a single-antenna OFDM system, and the system parameters are as follows:

[0028] The system bandwidth is 2MHz; the radio frequency is 339MHz; the digital intermediate frequency is 12.8MHz; the subcarrier spacing ΔF is 31.25kHz; the number of IFFT / FFT points is 128; the number of data subcarriers is 48; It is (7, 21, 107, 121); the value of the 4 comb pilot symbols is [1, -1, 1, 1], and the polarity of the symbols is g(x)=x according to the generator polynomial 7 +x 4 The m-sequence change of length 127 of +1; the length of the cyclic prefix (CP) is 8μs; the length of the cyclic suffix is ​​1.25μs; the roll-off coefficient of the raised cosine window is 0.03125; the modulation method is QPSK; the duration of the wireless frame is 10ms; The frame header length in the frame is 10 OFDM symbols, and the data is 240 OFDM symbols.

[0029] The precision of the crystal oscillator at both ends of the system is set to 5ppm, and the frequency difference be...

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 LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method and belongs to the technical field of communication system signal processing. The LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method comprises the following steps that: the total quantity of phase rotation, caused by sampling frequency shift and carrier residual frequency shift, is calculated according to comb-type pilot frequency symbols of a transmitting end of an OFDM system, actual comb-type pilot frequency symbols of a corresponding receiving end of the OFDM system and a channel transmission function which is obtained through frequency domain channel estimation; modeling is performed for the total quantity of the phase rotation according to comb-type pilot frequency position numbers in the OFDM system; a coefficient matrix of corresponding dimensions is obtained based on the number of comb-type pilot frequencies; and finally, the joint estimation of the sampling frequency shift and the carrier residual frequency shift can be realized through using the least squares algorithm. The LS algorithm-based sampling frequency shift and carrier residual frequency shift joint estimation method of the invention can be applied to wireless communication scenes of indoor and outdoor walking as well as outdoor low / mediate-speed movement, and can reduce system pilot frequency cost, and at the same time, can track and compensate phase rotation real time caused by the sampling frequency shift and the carrier residual frequency shift.

Description

technical field [0001] The invention belongs to the technical field of communication system signal processing, and in particular relates to a joint estimation method applicable to sampling frequency offset and carrier residual frequency offset in a multi-carrier wireless communication system. Background technique [0002] Multi-carrier technology uses multiple subcarriers to transmit data symbols in parallel, which can effectively suppress the impact of multipath effects on system performance. In particular, the Orthogonal Frequency Division Multiplexing (OFDM) method can not only improve the spectral efficiency of the system through the orthogonality between subcarriers, but also greatly reduce the complexity of system implementation by using the Fast Fourier Transform (FFT) algorithm. Therefore, this technology has been widely used in standards such as the fourth generation mobile communication (4G) and wireless local area network IEEE802.11a / g / n. However, while having ex...

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): H04L27/38H04L27/26H04L25/02
Inventor 葛利嘉张振宇钱林杰韩辉罗健源郑鹤张君
Owner CHONGQING TELECOMMUNICATION INSTITUTE