Data overlap decoder

• US 5,010,558 A
• Filed: 09/29/1988
• Issued: 04/23/1991
• Est. Priority Date: 09/29/1988
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Yost, Richard A., Damerow, David H.
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): Huseman, Marianne
• Application Number:
  US07/250,697
• Time in Patent Office: 936 Days
• Field of Search: 375/18, 375/37, 375/38, 375/94, 375/101, 375/102, 375/118, 371/43, 340/146.2, 364/728.01, 364/724.12
• US Class Current: 375/259
• CPC Class Codes: H03M 13/05 using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits H03M13/2906 takes precedence

Abstract

A decoding signal processing mechanism preserves the use of a single high data rate encoder at a transmitter site, so that the input data may be continuously encoded and transmitted, while using multiple low data rate decoders at the receiver site in such a manner that "end effects" are avoided and the performance of high data rate decoding is attained. At the transmitter site, digital information signals are encoded at a first encoding rate and then transmitted over a communication channel to a receiver site. At the receiver site signals to be decoded are coupled to a respective one of a plurality of decoders which decode, at a second rate less than said first, encoding rate, respective overlapping blocks of received encoded digital information signals and derive respective portions of the digital information signals. The decoded outputs of the decoders are combined to recover the digital information signals. To accommodate overlapping blocks of encoded information signals each decoder includes a buffer delay (memory) for storing a respective sequential overlapping portion of the received encoded information signal. By controlling the storage of a respective portion of the encoded signals through its buffer delay, each decoder can effectively operate on a portion of the encoded signals that permits downstream reassembly of the original information signals without anomolies at the signal interface of successive decoded segments of the information signals.

Claims

1. For use with a communication system having a transmitter site whereat information signals are encoded at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded information signals that have been transmitted over said communication channel from said transmitter site are received, an apparatus for recovering said signals comprising:

a plurality of first means, each of which is coupled to receive said encoded information signals, for extracting, at a rate less than said encoding rate, a respective portion of said received encoded information signals that overlaps another portion of said information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

second means for combining extracted portions of the received encoded information signals decoded by said plurality of second means and thereby producing output signals corresponding to said information signals; and

wherein

each first means includes first memory means for storing a respective sequential overlapping portion of said received encoded information signals, and decoding means, coupled to said first memory means, for decoding signals stored therein at a rate lower than said first rate at which said information signals are encoded at said transmitter site and producing therefrom a portion of said information signals; and

wherein

each of said first means includes means for writing said respective overlapping portion of said received encoded information signals into said first memory means at a rate corresponding to the data rate of said received signals, and for coupling the contents of said first memory means to said decoding means at a clock rate corresponding to said lower rate.

2. For use with a communication system having a transmitter site whereat information signals are encoded at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded information signals that have been transmitted over said communication channel from said transmitter site are received, an apparatus for recovering said signals comprising:

a plurality of first means, each of which is coupled to receive said encoded information signals, for extracting, at a rate less than encoding rate, a respective portion of said received encoded information signals that overlaps another portion of said information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

second means for combining extracted portions of the received encoded information signals decoded by said plurality of second means and thereby producing output signals corresponding to said information signals; and

wherein

each first means includes first memory means for storing a respective sequential overlapping portion of said received encoded information signals, and decoding means, coupled to said first memory means, for decoding signals stored therein at a rate lower than said first rate at which said information signals are encoded at said transmitter site and producing therefrom a portion of said information signals; and

wherein

each of said first means further includes second memory means, coupled to said decoding means, for storing said portion of said information signals, and wherein said second means includes means for reading out said portion of said information signals stored in said second memory means; and

wherein

each of said first means include means for writing decoded signals from said decoding means into said second memory means at said lower rate and for reading out the contents of said second memory means at a clock rate corresponding tot he clock rate of said original information signals.

3. An apparatus according to claim 2, wherein each of said first means further includes second memory means, coupled to said decoding means, for storing said portion of said information signals, and wherein said second means includes means for reading out said portion of said information signals stored in said second memory means.

4. An apparatus according to claim 3, wherein each of said first means include means for writing decoded signals from said decoding means into said second memory means at said lower rate and for reading out the contents of said second memory means at a clock rate corresponding to the clock rate of said original information signals.

5. For use with a digital communication system having a transmitter site whereat digital information signals are encoded by an encoder at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded digital information signals that have been transmitted over said communication channel from said transmitter site are received, an apparatus for recovering said signals:

a plurality of sampling means, each of which is coupled to received said encoded digital information signals, for sampling, at a rate less than said encoding rate, a respective portion of said received encoded digital information signals that overlaps another portion of said encoded digital information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

output means for combining respective portions of the received encoded digital information signals sampled by said plurality of sampling means and thereby producing digital output signals corresponding to said digital information signals; and

wherein

each sampling means includes first memory means for storing a respective sequential overlapping portion of said received encoded digital information signals, and a decoder, coupled to said first memory means, for decoding signals stored therein at a rate lower than said first rate at which said digital information signals are encoded at said transmitter site and producing therefrom a portion of said digital information signals, and further including means for

writing said respective overlapping portion of said received encoded digital information signals into said first memory means at a rate corresponding to the data rate of said received signals, and for coupling the contents of said first memory means to said decoder at a clock rate corresponding to said lower rate.

6. For use with a digital communication system having a transmitter site whereat digital information signals are encoded by an encoder at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded digital information signals that have been transmitted over said communication channel from said transmitter site are received, an apparatus for recovering said signals:

a plurality of sampling means, each of which is coupled to receive said encoded digital information signals, for sampling, at a rate less than said encoding rate, a respective portion of said received encoded digital information signals that overlaps another portion of said encoded digital information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

output means for combining respective portions of the received encoded digital information signals sampled by said plurality of sampling means and thereby producing digital output signals corresponding to said digital information signals, and wherein

each sampling means includes first memory means for storing a respective sequential overlapping portion of said received encoded digital information signals, and a decoder, coupled to said first memory means, for decoding signals stored therein at a rate lower than said first rate at which said digital information signals are encoded at said transmitter site and producing therefrom a portion of said digital information signals, and wherein

said means further includes second memory means, coupled to said decoder, for storing said portion of said information signals, and including means for reading out said portion of said digital information signals stored in said second memory means, and further including

means for writing decoded signals from said decoder into said second memory means at said lower rate and for reading out the contents of said second memory means at a clock rate corresponding to the clock rate of said original digital information signals.

7. For use with a digital communication system having a transmitter site whereat digital information signals are encoded by an encoder at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded digital information signals that have been transmitted over said communication channel from said transmitter site are received, an apparatus for recovering said signals:

a plurality of sampling means, each of which is coupled to receive said encoded digital information signals, for sampling, at a rate less than said encoding rate, a respective portion of said received encoded digital information signals that overlaps another portion of said encoded digital information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

output means for combining respective portions of the received encoded digital information signals sampled by said plurality of sampling means and thereby producing digital output signals corresponding to said digital information signals; and

wherein

each sampling means includes first memory means for storing a respective sequential overlapping portion of said received encoded digital information signals, and a decoder, coupled to said first memory means, for decoding signals stored therein at a rate lower than said first rate at which said digital information signals are encoded at said transmitter site and producing therefrom a portion of said digital information signals, further including means for

writing said respective overlapping portion of said received encoded digital information signals into said first memory means at a rate corresponding to the data rate of said received signals, and for coupling the contents of said first memory means to said decoder at a clock rate corresponding to said lower rate, and

wherein said decoding means further includes second memory means, coupled to said decoder, for storing said portion of said digital information signals, and including means for reading out said portion of said digital information signals stored in said second memory means.

8. An apparatus according to claim 7, including means for writing decoded signals from said decoder into said second memory means at said lower rate and for reading out the contents of said second memory means at a clock rate corresponding to the clock rate of said original digital information signals.

9. For use with a communication system having a transmitter site whereat information signals are encoded at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded information signals that have been transmitted over said communication channel from said transmitter site are received, a method for recovering information signals from said received signals comprising the steps of:

(a) coupling respective overlapping portions of said encoded information signals to a plurality of sampling means, each of which has a sampling rate less than said encoding rate, and thereby extracts a respective portion of said received encoded information signals that overlaps another portion of said information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

(b) combining extracted portions of the received encoded information signals extracted in step (a) by said plurality of sampling means and thereby producing output signals corresponding to said information signals, and wherein

step (a) includes storing, in a first memory, a respective sequential overlapping portion of said received encoded information signals and extracting signals stored therein at a rate lower than said first rate at which said information signals are encoded at said transmitter site and producing therefrom a portion of said information signals, and

writing said respective overlapping portion of said received encoded information signals into said first memory at a rate corresponding to the data rate of said received signals, and coupling the contents of said first memory to a decoder at a clock rate corresponding to said lower rate.

10. For use with a communication system having a transmitter site whereat information signals are encoded at a first encoding rate and transmitted over a communication channel to a receiver site whereat encoded information signals that have been transmitted over said communication channel from said transmitter site are received, a method for recovering information signals from said received signals comprising the steps of:

(a) coupling respective overlapping portions of said encoded information signals to a plurality of sampling means, each of which has a sampling rate less than said encoding rate, and thereby extracts a respective portion of said received encoded information signals that overlaps another portion of said information signals the time of occurrence of which is different from the time of occurrence of said respective portion; and

(b) combining extracted portions of the received encoded information signals extracted in step (a) by said plurality of sampling means and thereby producing output signals corresponding to said information signals, and wherein

step (a) includes storing, in a first memory, a respective sequential overlapping portion of said received encoded information signals and extracting signals stored therein at a rate lower than said first rate at which said information signals are encoded at said transmitter site and producing therefrom a portion of said information signals, storing in a second memory, said portion of said information signals, and further including reading out said portion of said information signals stored in second memory, and writing extracted signals into said second memory at said lower rate and for reading out the contents of said second memory at a clock rate corresponding to the clock rate of said original information signals.