EP0471246A2
Expired / Lapsed
EP
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Digital cellular TDM system employing 6:1 packing of transcoded information
Assignee: Motorola Solutions Inc
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Filing: 1991-08-01
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Granted: —
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Expires: 2011-08-01
Abstract
Abstract A digital cellular time-division multiple access (TDMA) system including a cellular switch (100) and at least one base-site (120) employing 6:1 packing of transcoded information. The system incorporates the VSELP speech encoding algorithm to transcode data input from a cellular switch (100) and a unique packing scheme to compress six message channels (105-110) worth of transcoded data into one 20 msec, 160 frame information block for transmission in one TDM timeslot (201). The compressed transcoded data is transmitted to a base-site (120) on a T1 link where the six message channels (105-110) worth of transcoded data is un-packed and coded. The coded information is then separated into two groups of three air-interface timeslots where two separate transmitters (318, 320) transmit one group each of three air-interface timeslots on two separate radio carrier frequencies.
Inventors
- 👤 Nelson C. Hung
- 👤 John R. Welk
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 06:56
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2643; H04W; H04W88/00; H04W88/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
195 words
A digital radio time-division multiple access (TDMA) system including a land-line telephone system interface (100) and at least one base-site (120) which generates at least one radio carrier frequency, the digital radio time-division multiple access (TDMA) system utilizing an equipment synchronization scheme to maintain equipment synchronization when required, the digital radio time-division multiple access (TDMA) system characterized by: means for compressing information input from at least two message channels (105, 106) from the land-line telephone system (101) into one information block for transmission in one TDM timeslot (201); means for inserting (310) a block synchronization scheme into said one information block; means for reserving a portion of said information block for the equipment synchronization scheme; means for using a fraction of said reserved portion for said compressed information when equipment synchronization is not required; means for conveying (115) at least said one TDM timeslot (201) from the land-line telephone system interface (100) to a base-site (120); and means, coupled to said means for conveying (115), for converting said compressed information of at least said one TDM timeslot (201) to coded information for at least two information timeslots for radio transmission on a radio carrier frequency.
Claim 2
Dependent Claim
141 words
The digital radio TDMA system of claim 1 wherein said means for compressing is further characterized by: first means for obtaining (301) one hundred and sixty 8-bit samples from one (105) of six message channels and second means for obtaining (302) one hundred and sixty 8-bit samples from a second (106) of said six message channels; first means for transforming (301) said one hundred and sixty 8-bit samples into a first 160 bit group and second means for transforming (302) said one hundred and sixty 8-bit samples into a second 160 bit group; means for packing (310) at least said first 160 bit group and said second 160 bit group into said one information block; and means for adding (310) error control to said one information block for each of said packed first 160 bit group and second 160 bit group.
Claim 3
Dependent Claim
179 words
The digital radio TDMA system of claim 1 wherein said means for inserting (310) a block synchronization scheme in said one information block is further characterized by means for inserting a bit having a value of '0' into the most significant bit position of frame 1 and inserting bits having alternating values of '1' and '0' into the most significant bit positions for the subsequent 39 frames, a bit having a value of '1' into the most significant bit position of frame 41 and inserting bits having alternating values of '0' and '1' into the most significant bit positions for the subsequent 39 frames, a bit having a value of '0' into the most significant bit position of frame 81 and inserting bits having alternating values of '1' and '0' into the most significant bit positions for the subsequent 39 frames, and a bit having a value of '1' into the most significant bit position of frame 121 and inserting bits having alternating values of '0' and '1' into the most significant bit positions for the subsequent 39 frames.
Claim 4
Dependent Claim
169 words
The digital radio TDMA system of claim 1 wherein said means for converting is further characterized by: means for receiving (314) said at least one TDM timeslot (201); means for synchronizing (316) to said one information block transmitted in said at least one TDM timeslot (201); means for checking (316) error control disposed in said one information block for each of said multiplexed at least first 160 bit group and second 160 bit group; means for separating (316) multiplexed first 160 bit group and second 160 bit group disposed in said one information block; means for coding (316) said separated first 160 bit group to produce a first 324 bit group and said separated second 160 bit group to produce a second 324 bit group; and means for packing (316) said first 324 bit group into a first information timeslot for radio transmission on a first radio carrier frequency and said second 324 bit group into a second information timeslot for radio transmission on a second radio carrier frequency.
Claim 5
Dependent Claim
193 words
A digital radio time-division multiple access (TDMA) system including a land-line telephone system interface (100) and at least one base-site (120) which receives at least one radio carrier frequency, the digital radio time-division multiple access (TDMA) system utilizing an equipment synchronization scheme to maintain equipment synchronization when required, the digital radio time-division multiple access (TDMA) system characterized by: means for converting (316) coded information of at least two information timeslots received from radio transmission on a radio carrier frequency into one information block for transmission in one TDM timeslot (201); means for reserving a portion of said information block for the equipment synchronization scheme; means for using a fraction of said reserved portion for said compressed information when equipment synchronization is not required; means for conveying (117) at least said one TDM timeslot (201) from a base-site (120) to the land-line telephone system interface (100); means, coupled to said means for conveying (117), for synchronizing (312) to said one information block transmitted in at least said one TDM timeslot (201); and means, coupled to said means for conveying (117), for expanding (312) said compressed information of at least said one TDM timeslot (201).
Claim 6
Independent Claim
183 words
A method which transfers messages from a land-line telephone system interface (100) to at least one base-site (120) in a digital radio time-division multiple access (TDMA) system, the digital radio time-division multiple access (TDMA) system utilizing an equipment synchronization scheme to maintain equipment synchronization when required, the digital radio time-division multiple access (TDMA) system, the method characterized by the steps of: compressing information input from at least two message channels (105, 106) from a land-line telephone system (101) into one information block for transmission in one TDM timeslot (201); inserting a block synchronization scheme into said one information block; reserving a portion of said information block for the equipment synchronization scheme; using a fraction of said reserved portion for said compressed information when equipment synchronization is not required; conveying at least said one TDM timeslot (201) from the land-line telephone system interface (100) to a basesite (120); and converting said compressed information of said one TDM timeslot (201), conveyed from said land-line telephone system interface (100), to coded information for at least two information timeslots for radio transmission on a radio carrier frequency.
Claim 7
Dependent Claim
119 words
The method of claim 6 wherein said step of compressing is further characterized by the steps of: obtaining one hundred and sixty 8-bit samples from one (105) of six message channels and obtaining one hundred and sixty 8-bit samples from a second (106) of said six message channels; transforming said one hundred and sixty 8-bit samples into a first 160 bit group and transforming said one hundred and sixty 8-bit samples into a second 160 bit group; packing at least said first 160 bit group and said second 160 bit group into said one information block; and adding error control to said one information block for each of said packed first 160 bit group and second 160 bit group.
Claim 8
Dependent Claim
176 words
The method of claim 6 wherein said step of inserting a block synchronization scheme in said one information block is further characterized by the step of inserting a bit having a value of '0' into the most significant bit position of frame 1 and inserting bits having alternating values of '1' and '0' into the most significant bit positions for the subsequent 39 frames, a bit having a value of '1' into the most significant bit position of frame 41 and inserting bits having alternating values of '0' and '1' into the most significant bit positions for the subsequent 39 frames, a bit having a value of '0' into the most significant bit position of frame 81 and inserting bits having alternating values of '1' and '0' into the most significant bit positions for the subsequent 39 frames, and a bit having a value of '1' into the most significant bit position of frame 121 and inserting bits having alternating values of '0' and '1' into the most significant bit positions for the subsequent 39 frames.
Claim 9
Dependent Claim
151 words
The method of claim 6 wherein said step of converting is further characterized by the steps of: receiving said at least one TDM timeslot (201); synchronizing to said one information block transmitted in said at least one TDM timeslot (201); checking error control disposed in said one information block for each of said multiplexed at least first 160 bit group and second 160 bit group; separating multiplexed first 160 bit group and second 160 bit group disposed in said one information block; coding said separated first 160 bit group to produce a first 324 bit group and said separated second 160 bit group to produce a second 324 bit group; and packing said first 324 bit group into a first information timeslot for radio transmission on a first radio carrier frequency and said second 324 bit group into a second information timeslot for radio transmission on a second radio carrier frequency.
Claim 10
Independent Claim
117 words
A method which transfers messages from at least one base-site (120) to a land-line telephone system interface (100) in a digital radio time-division multiple access (TDMA) system, the method characterized by the steps of: converting coded information of at least two information timeslots received from radio transmission on a radio carrier frequency into one information block for transmission in one TDM timeslot (201); conveying at least said one TDM timeslot (201) from a base-site (120) to the land-line telephone system interface (100); synchronizing to said one information block transmitted in at least said one TDM timeslot (201) conveyed from a base-site (120); and expanding said compressed information of said TDM timeslot (201) conveyed from a base-site (120).
References Cited (Backward Citations)
No citation records indexed.
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