Voice compression system and method

• US 5,592,586 A
• Filed: 08/11/1994
• Issued: 01/07/1997
• Est. Priority Date: 01/08/1993
• Status: Expired due to Fees

• Current Assignee: Multi-Tech Systems Incorporated
• Original Assignee: Multi-Tech Systems Incorporated
• Inventors: Young, Steve, Maitra, Sidhartha, Thanawala, Ashish
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): ONKA, THOMAS
• Application Number:
  US08/289,297
• Time in Patent Office: 880 Days
• Field of Search: 395/2.28, 395/2.29, 395/2.3
• US Class Current: 704/220
• CPC Class Codes: G10L 19/04 using predictive techniques
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/6424 Access arrangements
• CPC Class Codes: H04L 2012/6427 Subscriber Access Module; Concentrator; Group equipment
• CPC Class Codes: H04L 2012/6459 Multiplexing, e.g. TDMA, CDMA
• CPC Class Codes: H04L 2012/6475 N-ISDN, Public Switched Telephone Network [PSTN]
• CPC Class Codes: H04L 2012/6481 Speech, voice
• CPC Class Codes: H04L 2012/6491 Echo cancellation
• CPC Class Codes: H04L 2012/6494 Silence suppression
• CPC Class Codes: H04L 27/3416 in which the information is carried by both the individual signal points and the subset to which the individual points belong, e.g. using coset coding, lattice coding, or related schemes
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 1/247 Telephone sets including user guidance or feature selection means facilitating their use user interfaces specially adapted for cordless or mobile telephones H04M1/724
• CPC Class Codes: H04M 1/2473 Telephone terminals interfacing a personal computer, e.g. using an API (Application Programming Interface) details of API H04M7/0021
• CPC Class Codes: H04M 1/2477 for selecting a function from a menu display H04M1/2474 takes precedence
• CPC Class Codes: H04M 1/253 Telephone sets using digital voice transmission
• CPC Class Codes: H04M 1/57 : Arrangements for indicating or recording the number of the calling subscriber at the called subscriber's set at the operator set in a manual exchange H04M5/20
• CPC Class Codes: H04M 1/6033 : for providing handsfree use or a loudspeaker mode in telephone sets arrangements for preventing acoustic echo H04M9/08
• CPC Class Codes: H04M 1/6505 : storing speech in digital form
• CPC Class Codes: H04M 1/663 : Preventing unauthorised calls to a telephone set
• CPC Class Codes: H04M 11/06 : Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 11/064 : Data transmission during pauses in telephone conversation
• CPC Class Codes: H04M 11/068 : using time division multiplex techniques; integrated services digital networks H04Q11/0428
• CPC Class Codes: H04M 2203/4509 : Unified messaging with single point of access to voicemail and other mail or messaging systems unified messaging in packet switching networks H04L51/56
• CPC Class Codes: H04M 3/002 : Applications of echo suppressors or cancellers in telephonic connections in two-way loud-speaking telephone systems H04M9/08, echo suppressors or cancellers per se H04B3/20
• CPC Class Codes: H04M 3/42 : Systems providing special services or facilities to subscribers specially adapted for wireless communication networks H04W4/00
• CPC Class Codes: H04M 3/436 : Arrangements for screening incoming calls , i.e. evaluating the characteristics of a call before deciding whether to answer it based on the calling party profile H04M3/42059; based on location H04M3/42348; based on presence H04M3/42365; diversion H04M3/54
• CPC Class Codes: H04M 3/5307 : for recording messages comprising any combination of audio and non-audio components
• CPC Class Codes: H04M 3/533 : Voice mail systems
• CPC Class Codes: H04M 3/567 : Multimedia conference systems
• CPC Class Codes: H04M 7/0027 : Collaboration services where a computer is used for data transfer and the telephone is used for telephonic communication
• CPC Class Codes: H04M 7/0057 : Services where the data services network provides a telephone service in addition or as an alternative, e.g. for backup purposes, to the telephone service provided by the telephone services network
• CPC Class Codes: H04M 7/006 : Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/1295 : Details of dual tone multiple frequency signalling
• CPC Class Codes: H04N 1/00204 : with a digital computer or a digital computer system, e.g. an internet server programmed control between transmitter and receiver or between image input and image output device H04N1/32561
• CPC Class Codes: H04N 1/00206 : Transmitting or receiving computer data via an image communication device, e.g. a facsimile transceiver H04N1/00236 takes precedence
• CPC Class Codes: Y10S 379/908 : Multimedia

Abstract

A system for performing voice compression which includes, a conversion means for converting analog voice signals into discrete samples of digital voice data and collecting the discrete samples into segments, with a means for dividing the segments into subsegments and for producing therefrom a current voice subsegment. A pitch prediction means is used for determining the long term predicted gain of the current voice subsegment by comparing the current voice subsegment to reconstructed voice samples to produce a pitch predictor gain and a lag component and a pitch filter means is used for pitch filtering the current voice subsegment based on the pitch predictor gain and the lag component which then produces long term residual samples. The system includes a means for scaling the long term residual samples based on the peak amplitude of the long term residual samples to produce normalized long term residual samples and a means including a code book stored in a memory for locating a single memory address of a closest match between the normalized long term residual samples and the stored distinct normalized long term residual samples. The system includes an output means for providing the distinct memory address, the pitch predictor gain, the lag component and the peak amplitude for each voice subsegment and a means to reconstruct these samples based on these parameters.

Claims

1. A system for performing voice compression, comprising:

voice interface means including a voice input device for receiving analog voice signals from a user;

conversion means for converting the analog voice signals into discrete samples of digital voice data and collecting the discrete samples into segments;

means for dividing the segments into subsegments and for producing therefrom a current voice subsegment;

pitch prediction means for determining the long term predicted gain of the current voice subsegment by comparing the current voice subsegment to reconstructed voice samples to produce a pitch predictor gain and a lag component;

pitch filter means for pitch filtering the current voice subsegment based on the pitch predictor gain and the lag component and for producing therefrom long term residual samples;

means for determining the peak amplitude of the long term residual samples;

means for scaling the long term residual samples based on the peak amplitude to produce normalized long term residual samples;

means including a code book stored in a memory for comparing the normalized long term residual samples to stored distinct normalized long term residual samples stored in the memory and for locating a single memory address of a closest match between the normalized long term residual samples and the stored distinct normalized long term residual samples;

means for producing normalized reconstructed long term residual samples from the stored distinct normalized long term residual samples at the single memory address of the closest match;

means for producing a reconstructed long term residual samples from the normalized reconstructed long term residually samples;

means for inverse pitch filtering the reconstructed long term residual samples based upon the pitch predictor gain and the lag component and for producing therefrom the reconstructed voice samples; and

output means for providing the distinct memory address, the pitch predictor gain, the lag component and the peak amplitude for each voice subsegment.

2. A method for compression speech information, comprising the steps of:

receiving an analog speech signal;

digitizing the speech signal into a discrete samples of distal voice data and collecting the discrete samples into segments;

dividing the segments into subsegments and producing at least one current subsegment;

comparing the current subsegment to a reconstructed voice sample;

determining the pitch predictor gain of the current subsegment;

determining the lag component of the current subsegment;

pitch filtering the current subsegment using the pitch predictor gain and the lag component and producing long term residual samples;

detecting the amplitude of the long term predicted residual samples;

scaling the long term predicted residual signal to produce a normalized long term predicted residual samples;

comparing the normalized long term predicted residual samples to stored distinct normalized long term predicted residual samples stored in a memory, and for locating a single memory address of the closest match between the distinct brutalized long term predicted residual samples and the stored distinct normalized long term predicted residual samples;

producing normalized reconstructed long term residual samples from the stored distinct normalized long term residual samples at the, single memory address of the closest match;

producing reconstructed long term residual samples from the normalized reconstructed long term residual samples; and

inverse pitch filtering the reconstructed long term residual samples based upon the pitch predictor gain and the lag component and producing therefrom the reconstructed voice samples.