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US4882726A Expired / Lapsed US ⏱️ 0.0 years remaining

Full duplex modem system for differing data bit rates

Assignee: Motorola Solutions Canada Inc
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Filing: 1987-11-23
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Granted: 1989-11-21
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Expires: 2007-11-23
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Abstract

Abstract A pair of full duplex modems are connected and each is designed to transmit to the other at the same predetermined band rates. One modem is connected to receive data bits for transmission over the channel at a predetermined first (and fast) rate and to transmit its received data bits at a integral number of first transmission bits per band. The other modem is connected to receive data bits for transmission over the channel at a rate slower than the band rate and is designed to sequentially encode blocks of said slower rate data bits into a larger number of second transmission bits for transmission over said channel at an integral number of second transmission bits per band. Means forming part of said one modem for converting said second transmission bits into the slower rate data bits.

Inventors

  • 👤 Gordon R. Lang
  • 👤 Fred M. Longstaff

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 12:08
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4906; H04L25/4908; H04L25/02; H04L25/05; Y; Y10; Y10S; Y10S370/00; Y10S370/914

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 170 words
In a communication system: a pair of full duplex modems connected by a channel, each modem being designed to transmit to the other at the same predetermined baud rate, one of said modems being designed to receive a first series of data bits at a predetermined first rate for transmission over said channel and to transmit said received bits as first transmission bits over said channel as an integral number of first transmission bits per baud, the other of said modems being designed to receive a second series of data bits at a data bit rate slower than the predetermined baud rate, for transmission over said channel, means forming part of said other modem for sequentially encoding blocks of said second series of data bits in blocks into a larger number of second transmission bits for transmission over said channel at an integral number of second transmission bits per baud means forming part of said one modem for decoding said second transmission bits into said second series of data bits.
Claim 2
Dependent Claim 170 words
In a communication system: a pair of full duplex modems connected by a channel, each modem being designed to transmit to the other at the same predetermined baud rate, one of said modems being designed to receive a first series of data bits at a predetermined first rate for transmission over said channel and to transmit said received bits as first transmission bits over said channel as an integral number of first transmission bits per baud, the other of said modems being designed to receive a second series of data bits at a data bit rate slower than the predetermined baud rate, for transmission over said channel, means forming part of said other modem for sequentially encoding blocks of said second series of data bits in blocks into a larger number of second transmission bits for transmission over said channel at an integral number of second transmission bits per baud means forming part of said one modem for decoding said second transmission bits into said second series of data bits.
Claim 3
Dependent Claim 75 words
A full duplex modem being connected to a channel to receive and transmit thereon at the same predetermined baud rate, means in said modem for receiving data bits for transmission over said channel, at a predetermined data bit rate less than said predetermined baud rate and for converting said data bits in blocks into a larger number of transmission bits, to provide an integral number of transmission bits per baud for transmission along said channel.
Claim 4
Dependent Claim 75 words
A full duplex modem being connected to a channel to receive and transmit thereon at the same predetermined baud rate, means in said modem for receiving data bits for transmission over said channel, at a predetermined data bit rate less than said predetermined baud rate and for converting said data bits in blocks into a larger number of transmission bits, to provide an integral number of transmission bits per baud for transmission along said channel.
Claim 5
Dependent Claim 36 words
In a communications system as claimed in claim 1 where the baud rate is 2400, the slower bit rate is 300 bps and each block of 8 said data bits is encoded into 128 transmission bits.
Claim 6
Dependent Claim 36 words
In a communications system as claimed in claim 2 where the baud rate is 2400, the data bit rate is 300 bps and the data bits are encoded in blocks of 8 into 128 transmission bits.
Claim 7
Dependent Claim 46 words
In a communications system as claimed in claim 3 wherein, in said sequentially encoding means said eight bits per block are used to uniquely select coordinates comprising a row of a 128×128 Hadamand matrix or its negative and said transmission bits are based on said coordinates.
Claim 8
Dependent Claim 48 words
In a communications system as claimed in claim 4 wherein, in said receiving and converting means, said eight bits per block are used to uniquely select coordinates which are a row of a 128×128 Hadamard matrix or its negative and said transmission bits are based on said coordinates.
Claim 9
Dependent Claim 43 words
In a communications system as claimed in claim 1 wherein said means for encoding said blocks of data bits provides from said blocks said second transmission bits determined in accord with the coordinates selected from rows of a Hadamard matrix or its negative.
Claim 10
Dependent Claim 36 words
In a full duplex modem as claimed in claim 1 wherein said encoding means provides from said blocks transmission bits determined in accord with coordinates selected from the rows of a Hadmand matrix or its negative.
Claim 11
Dependent Claim 103 words
A full duplex modem designed for reception and transmission over a channel at a predetermined baud rate, designed to receive from said channel first transmission bits at a rate which is an integral number of bits per baud, and having means designed to be supplied with data bits at a rate which is a fractional number of bits per baud, means for converting said bits in blocks into a larger number of second transmission bits with values having a unique relationship to a block of said bits at an integral number per baud and means for transmitting said second bits on said channel.
Claim 12
Dependent Claim 103 words
A full duplex modem designed for reception and transmission over a channel at a predetermined baud rate, designed to receive from said channel first transmission bits at a rate which is an integral number of bits per baud, and having means designed to be supplied with data bits at a rate which is a fractional number of bits per baud, means for converting said bits in blocks into a larger number of second transmission bits with values having a unique relationship to a block of said bits at an integral number per baud and means for transmitting said second bits on said channel.
Claim 13
Dependent Claim 58 words
In combination with the full duplex modem of claim 9, a second full duplex modem connected to said first-mentioned modem over said channel; said second modem being designed for reception and transmission over said channel at said predetermined baud rate, means in said second modem for decoding said second transmission bits into the said blocks of data bits.
Claim 14
Dependent Claim 32 words
A full duplex modem, as claimed in claim 9 wherein said predetermined baud rate is 2400 and said data bit rate is 300 bps, said second transmission bit rate is 4800 bps.
Claim 15
Dependent Claim 56 words
In combination with the full duplex modem of claim 10, a second full duplex modem, connected over said channel to said first mentioned modem, said second modem being designed for reception and transmission over said channel at 2400 baud, means in said second modem for decoding said second transmission bits into said blocks of data bits.
Claim 16
Dependent Claim 24 words
A full duplex modem as claimed in claim 9 wherein said encoding is determined by rows selected from a Hadamard matrix or its negative.
Claim 17
Dependent Claim 25 words
A full duplex modem as claimed in claim 11 wherein said encoding is determined by rows selected from a 128×128 Hadamard matrix or its negative.
Claim 18
Dependent Claim 23 words
In a communications system as claimed in claim 5 wherein said encoding means includes means for modifying said coordinates to provide differential encoding.
Claim 19
Dependent Claim 21 words
In a communications system as claimed in claim 5 wherein said encoding means includes means for modifying said coordinates by rotations.
Claim 20
Dependent Claim 23 words
In a communications system as claimed in claim 8 wherein said encoding means includes means for modifying said coordinates to provide differential encoding.
Claim 21
Dependent Claim 21 words
In a communications system as claimed in claim 8 wherein said encoding means includes means for modifying said coordinates by rotations.

References Cited (Backward Citations)

US3775751A Cited
US4069392A Cited
US4477898A Cited
US4641303A Cited
US4734920A Cited
US4680781A Cited
US4700358A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-11-20 1993-05-22 1993-11-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-11-20 1997-05-22 1997-11-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-11-20 2001-05-22 2001-11-21 $7700.00 Window Closed / Lapsed

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