Improved method for generating in-band on-channel digital-analog audio broadcasting signals

A broadcast signal and generation method technology, applied in the direction of broadcast information generation, simultaneous broadcast of multiple pieces of information, multi-frequency code system, etc., can solve the problems of signal leakage, signal energy loss, etc.

Active Publication Date: 2013-07-24
SHENZHEN SIKAIWEI ELECTRONICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0017] Although the method disclosed in the patent application has successfully produced digital-analog audio broadcasting signals with the same frequency in-band, the out-of-band energy leakage of the signal is serious, which means that the filtered signal loses more energy

Method used

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  • Improved method for generating in-band on-channel digital-analog audio broadcasting signals
  • Improved method for generating in-band on-channel digital-analog audio broadcasting signals
  • Improved method for generating in-band on-channel digital-analog audio broadcasting signals

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0078] Proceed as follows:

[0079] Ⅰ. Obtaining analog sound broadcasting signals;

[0080] In this example, let m(t) denote the analog sound broadcasting signal, f c is the FM carrier. FM modulated signal x FM Expressed as

[0081] x FM =cos[α(t)]

[0082] where a(t) is the phase function given by

[0083] α ( t ) = 2 π f c t + 2 π f d ∫ - ∞ t m ( t ) dτ

[0084] here f d denotes the maximum frequency offset, and assumes

[0085] max t | m ( t ) | = 1

[0086] Let the discrete-time ...

Embodiment 2

[0110] Steps Ⅰ, Ⅱ, Ⅲ and Ⅴ are the same as in embodiment 1, and the digital-analog mixed signal S in step Ⅳ is obtained according to the following formula:

[0111] S=(jx 0 +d 0 , kx 1 +d 0 ,jx 2 +d1 , kx 3 +d 1 ,…..jx 2m +d m , kx 2m+1 +d m  …..) jx 2m +kx 2m+1 It can also be decomposed by mathematical formulas to get x 2m and x 2m+1 In the above formula, j and k are any non-zero integers. In this embodiment, j and k are both taken as 2, namely

[0112] S=(2x 0 +d 0 ,2x 1 +d 0 ,2x 2 +d 1 ,2x 3 +d 1 ,…,2x 2m +d m ,2x 2m+1 +d m ...).

[0113] Adjacent "plus plus ++" in the above mixed signal S can also use "plus minus +-" operation, that is

[0114] S=(jx 0 +d 0 , kx 1 -d 0 ,jx 2 +d 1 , kx 3 -d 1 ,…..jx 2m +d m , kx 2m+1 -d m  …..). Embodiment 3 of an improved in-band same-frequency digital-to-analog audio broadcasting signal generation method

Embodiment 3

[0115] Steps Ⅰ, Ⅱ, Ⅲ and Ⅴ are the same as in embodiment 1, and the digital-analog mixed signal S in step Ⅳ is obtained according to the following formula:

[0116] S=(…x 2(m-1) +d m-2L ,….x 2(m-1)+L +d m-L-1 ,x 2m +d m-L ,x 2m+1 +d m-L+1 ,….x 2m+L-1 +d m-1 ,x 2m+L +d m ...)

[0117] In this embodiment, L is 5,

[0118] S=(…x 2(m-1) +d m-10 ,….x 2(m-1)+5 +d m-6 ,x 2m +d m=5 ,x 2m+1 +d m-4 ,….x 2m+4 +d m-1 ,x 2m+5 +d m ...).

[0119] Similarly, the digital signal d m It may not be repeated in adjacent data blocks. For example, the repeated interval is L digital signals, and then, as in the above two methods, "addition and subtraction +-" or "addition and ++" processing are performed with analog signals, and the obtained digital signals are respectively like Figure 8 , Figure 9 shown in .

[0120] Therefore, to sum up, as long as the analog-digital signals transmitted by the transmitter are mixed according to a mathematical relationship in the time...

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Abstract

The invention relates to an improved method for generating in-band on-channel digital-analog audio broadcasting signals. The method comprises a step of obtaining and digitalizing analog audio broadcasting signals and transmitting the obtained digitalized analog audio broadcasting signals in the same broadcasting channel, and a step of duplicating digital signals of another path in adjacent signal frames. Time domain hybrid is carried out on an analog signal and a digital signal, an analog audio broadcasting signal x2m plus a corresponding digital broadcasting signal dm equals x2m+dm, an analog audio broadcasting signal x2m+1 plus the corresponding digital broadcasting signal equals x2m+1+dm, wherein the analog broadcasting signal x2m and the analog broadcasting signal x2m+1 are in adjacent signal frames, and a digital mixed signal is transmitted in the same broadcasting channel. A digital-analog hybrid signal j*x2m+dm is obtained by a manner that the x2m multiplies a nonzero integer j, and a digital-analog hybrid signal k*x2m+dm is obtained by a manner that the x2m+1 multiplies a nonzero integer k, or the digital signal dm recurs after an interval of L digital signals to be mixed with the analog signal in an add-subtract or add-add mode. The digital-analog hybrid signal with frequency spectrums completely overlapped is obtained, frequency bands are saved, much energy can be accumulated in a preset bandwidth, leakage out of a band is small, and signal energy loss is reduced.

Description

technical field [0001] The invention belongs to the technical field of digital audio broadcasting, and in particular relates to a method for generating an improved Time Domain Overlapping-In Band On Channel (TDO-IBOC) digital-to-analog audio broadcasting signal with time domain overlapping. Background technique [0002] With the rapid development of TV, the Internet, and mobile communication networks, traditional FM audio broadcasting has become a less important media method, and digital transformation is urgently needed to stimulate new business models and profit methods. [0003] Existing FM digital technology solutions mainly include Digital Audio Broadcasting (DAB, Digital Audio Broadcasting) in Europe, Digital Radio Mondiale (DRM, Digital Radio Mondiale) in Europe, and High Definition Radio (HD Radio) in the United States. [0004] It is difficult to achieve a smooth transition between the DAB system and the existing FM system. Moreover, DAB radios are expensive and di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L5/00H04H60/07H04H20/31
CPCY02D30/70
Inventor 张豫伟陈曦门爱东黄建忠张光华罗建平
Owner SHENZHEN SIKAIWEI ELECTRONICS CO LTD
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