Digital videocast modulating method and device

A technology of digital TV broadcasting and signal modulation, applied in high-definition television systems, multi-frequency code systems, etc., can solve the problems of transmitting CP power consumption, high peak-to-average power ratio, reducing timing synchronization speed and accuracy, etc. Fast synchronization, low complexity, and power saving effects

Inactive Publication Date: 2007-03-14
HUAWEI TECH CO LTD
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] From the above modulation system, CP needs to be inserted into the signal after OFDM modulation. Since CP and data have certain correlation characteristics, the receiver can complete timing synchronization by relying on CP. However, transmitting CP needs to consume a certain amount of power.
However, fading channels, special values ​​of data signals, etc. will deteriorate the correlation between CP and data, thus greatly reducing the speed and accuracy of timing synchronization
[0005] Moreover, for all digital broadcasting systems based on OFDM modulation, there is a common problem: the peak-to-average power ratio (PAPR) is generally high, which will directly lead to a decrease in the use efficiency of the power amplifier of the transmitter, especially when the number of carriers is small. When it is large, such as 8k mode of DVB-T, the power amplifier efficiency of the transmitter is very low
Unfortunately, the existing DVB-T system does not take this issue into account

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
  • Digital videocast modulating method and device
  • Digital videocast modulating method and device
  • Digital videocast modulating method and device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0044] The present invention does not perform CP insertion processing on the OFDM modulated data signal, but fills the original guard interval with 0, that is, there is no signal, thus saving power consumption. However, because zero filling cannot improve the speed and accuracy of timing synchronization, the present invention introduces a preamble into each frame, and the preamble can be designed to have good correlation characteristics, so that the receiver can quickly and accurately time the timing.

[0045] Referring to shown in Figure 2, realizing the method of the present invention comprises the following steps:

[0046] Step 200: Generate and store pre-pilot signals, synchronization band symbols and pilot symbols. Both synchronization symbols and pilot symbols can use PN sequences, that is, generate a series of pseudo-random numbers with values ​​{0, 1}, and then map (0->1, 1->-1) into required symbols through BPSK.

[0047] The synchronization band symbol includes two ...

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

This invention discloses one digital television broadcast signal modulation method, which comprises the following steps: multiplying data signals, pre-generated frequency characters and synchronous wave load and zero wave load distributed symmetrically, wherein, the said guidance characters occupies one part wave load with each load wave not adjacent distributed; the time area signals adds protection isolation with zero filled to form one OFDM character by use of more than one OFDM character and one front frequency signal to generate base band send signals.

Description

technical field [0001] The invention relates to the field of digital TV broadcasting, in particular to a modulation method and device for digital TV broadcasting. Background technique [0002] Digital TV broadcasting is a research and application hotspot in the field of broadcasting technology at present, and many countries have launched their own digital TV broadcasting systems one after another. At present, there are various modulation techniques for digital TV broadcasting, among which, the DVB-T standard adopts Orthogonal Frequency Division Multiplexing (OFDM) modulation in terms of transmission, which belongs to the multi-carrier transmission technique. [0003] Referring to FIG. 1 , the modulation structure of the transmitter defined by the DVB-T standard includes an OFDM modulation unit 100 , a guard interval insertion (CP) unit 104 and a framing unit 105 . Wherein, the OFDM modulation unit 100 includes a serial / parallel conversion unit 101 , an inverse fast Fourier ...

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): H04L27/26H04N7/015
Inventor 王艺段为明
Owner HUAWEI TECH CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap