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

precision timing

A precise and timing technology, used in digital transmission systems, synchronization devices, electrical components, etc., to solve problems such as partial loss of frame start points, high preset thresholds, and low preset thresholds.

Active Publication Date: 2019-12-03
HARMAN INT IND INC
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For example, in some cases the preset threshold may be too low and noise can be mistakenly identified as a data frame
In some cases the preset threshold may be too high and the beginning part of the frame may be lost

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
  • precision timing
  • precision timing
  • precision timing

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0083] Experiments were performed under the following conditions.

[0084] Vector of delay values ​​(ns): [0 100 200 300 400 500 600 700];

[0085] Vector of tap power (dB): [0-11.2-19-21.9-25.3-24.4-28.0-26.1];

[0086] Doppler frequency: 1kHz;

[0087] Threshold for conventional methods: 0.2;

[0088] SNR range: -1dB~20dB;

[0089] Length of short training sequence; 16.

[0090] In the experiment, the first timing metric was calculated according to equation (6):

[0091] a(d)=M1 (d)·M 1 (d+16) Equation (6)

[0092] in

[0093] Equation (7).

[0094] In this experiment, a set of 9 first timing metrics that are evenly spaced by the length of the short training sequence with the largest sum within the period identified by the coarse timing procedure is identified.

[0095] Figure 5 Bit error rate plots illustrating the conventional method and the method according to one embodiment obtained under the above conditions. Line 301 represents the bit error rate of the ...

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 provides a precise timing method. The method includes: calculating the value of a first timing metric function based on the cross-correlation between the received signal and M training sequences within a certain period of time to obtain a plurality of sets of X values ​​spaced according to a specific pattern; respectively calculating summing the plurality of sets of X values; and determining a start point for a data frame based on the computed sum.

Description

technical field [0001] The present application relates generally to precision timing in communication systems, and more particularly to precision timing in OFDM communication systems. Background technique [0002] The IEEE 802.11p protocol, also known as WAVE: Wireless Access in Vehicular Environments, is an approved amendment of IEEE 802.11. It is an extension of IEEE 802.11 and conforms to the corresponding application in Intelligent Transportation System (ITS: Intelligent Transportation System). [0003] Similar to other 802.11 family members, 802.11p's frame synchronization mainly depends on short and long training sequences. figure 1 Examples of these training sequences are illustrated in . In this example, there are 10 short training sequences t 1 ~t 10 and two long training sequences T 1 ~T 2 , and the total training time is 32 μs. [0004] In some conventional approaches, frame synchronization is decomposed into a coarse timing procedure and a fine timing proc...

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 Patents(China)
IPC IPC(8): H04L27/26
CPCH04L27/2656H04L27/2671H04L27/2675H04W56/003H04L27/2646H04L67/12
Inventor 裴文江郝金光王开杨曾
Owner HARMAN INT IND INC