JPS553266A - Adaptive dpcm system and its device - Google Patents

Adaptive dpcm system and its device

Info

Publication number
JPS553266A
JPS553266A JP7603378A JP7603378A JPS553266A JP S553266 A JPS553266 A JP S553266A JP 7603378 A JP7603378 A JP 7603378A JP 7603378 A JP7603378 A JP 7603378A JP S553266 A JPS553266 A JP S553266A
Authority
JP
Japan
Prior art keywords
quantizer
transmitted
quantization
aural
code
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP7603378A
Other languages
Japanese (ja)
Other versions
JPS6244450B2 (en
Inventor
Taku Arazeki
Kazunori Ozawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP7603378A priority Critical patent/JPS553266A/en
Publication of JPS553266A publication Critical patent/JPS553266A/en
Publication of JPS6244450B2 publication Critical patent/JPS6244450B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)
  • Error Detection And Correction (AREA)

Abstract

PURPOSE: To secure the identical size for the quantization steps of the reception device and thus to prevnt the quality deterioraion caused by the code error by providing the resetting function to part of the codes to be transmitted for the device use for the aural band compression.
CONSTITUTION: In the adaptive DPCM system in which the difference between the signals to be transmitted and the expected value of these signals are quantized by the adaptive quantization system, the difference between the expected value formed through expecting unit 40 and the aural signal is obtained by subtractor 10. And two threshold levels are given to control circuit 60 which sets the quantization step sizes to the same value for both quantizer 20 and reverse quantizer 32 in case the quantization step size becomes within the prescribed region. In addition, multiplexer 70 is provided to select and deliver the output of quantizer 20 or the prescribed code based on the output of circuit 60. And the resetting function is given to part of the code to be transmitted to secure the identical size for the quantization steps of reverse quantizer 32 of the reception device. Thus, the code error is corrected with every aural cycle.
COPYRIGHT: (C)1980,JPO&Japio
JP7603378A 1978-06-22 1978-06-22 Adaptive dpcm system and its device Granted JPS553266A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7603378A JPS553266A (en) 1978-06-22 1978-06-22 Adaptive dpcm system and its device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7603378A JPS553266A (en) 1978-06-22 1978-06-22 Adaptive dpcm system and its device

Publications (2)

Publication Number Publication Date
JPS553266A true JPS553266A (en) 1980-01-11
JPS6244450B2 JPS6244450B2 (en) 1987-09-21

Family

ID=13593501

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7603378A Granted JPS553266A (en) 1978-06-22 1978-06-22 Adaptive dpcm system and its device

Country Status (1)

Country Link
JP (1) JPS553266A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61107831A (en) * 1984-10-31 1986-05-26 Kowa Co Signal processor

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61107831A (en) * 1984-10-31 1986-05-26 Kowa Co Signal processor

Also Published As

Publication number Publication date
JPS6244450B2 (en) 1987-09-21

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