US4852090A
Expired / Lapsed
US
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TDMA communications system with adaptive equalization
Assignee: Motorola Solutions Inc
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Filing: 1988-04-13
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Granted: 1989-07-25
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Expires: 2008-04-13
Abstract
Abstract A method and means for reducing multipath interference distortion in a time-division multiple access (TDMA) communications system is disclosed. A transmitting station (100) formats one or more equalizer synchronization words with a first user's data word, time-multiplexes this formatted user message with at least one other user message, and transmits the combined signal. The receiving station (200) receives the transmitted TDMA signal, de-multiplexes the first user message from the other user messages, and equalizes the time delay spread characteristics of the data word portion of the first user message (or a stored version of such) in response to this de-multiplexing. Performing the adaptive equalization process more than once per user time slot provides an even higher data throughout for the system. Storing the first user message in a data buffer permits the adaptive equalization process to be performed in non-real time, thereby lowering the required signal processing data rate in any particular receiver.
Inventors
- 👤 David E. Borth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:22
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/005; H04B7/24; H04B7/26; H04B7/2643; H04L; H04L7/00; H04L7/04; H04L7/041; H04L7/042
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
144 words
A time division multiple access (TDMA) communication system comprising: a transmitting station including means for interleaving a plurality of first predetermined synchronization words with a plurality of first data words to form a first user message; means for multiplexing said first user message with at least one other user message to form a TDMA signal; means for transmitting said TDMA signal; and a receiving station including means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and means for equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 2
Dependent Claim
144 words
A time division multiple access (TDMA) communication system comprising: a transmitting station including means for interleaving a plurality of first predetermined synchronization words with a plurality of first data words to form a first user message; means for multiplexing said first user message with at least one other user message to form a TDMA signal; means for transmitting said TDMA signal; and a receiving station including means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and means for equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 3
Dependent Claim
43 words
The TDMA communication system according to claim 1, wherein subsequent synchronization words of said plurality of first predetermined synchronization words are comprised of a fewer number of bits than the first predetermined synchronization word, said subsequent synchronization words functioning as sync update words.
Claim 4
Dependent Claim
29 words
The TDMA communication system according to claim 2, wherein said sync update words exhibit a word length of less than one-half of the length of said first synchronization word.
Claim 5
Dependent Claim
45 words
The TDMA communication system according to claim 1, wherein said equalizing means includes means for adapting the time delay spread parameters of said equalizing means in response to the reception of each of said first predetermined synchronization word portions of said de-multiplexed first user message.
Claim 6
Dependent Claim
30 words
The TDMA communication system according to claim 4, further comprising means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal.
Claim 7
Dependent Claim
46 words
The TDMA communication system according to claim 5, wherein said equalizing means equalizes the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 8
Dependent Claim
38 words
The TDMA communication system according to claim 6, wherein said equalizing means performs both the adaptation and the equalization functions at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 9
Dependent Claim
130 words
A time division multiple access (TDMA) communication receiving station for receiving a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a plurality of first predetermined synchronization words interleaved with a plurality of first data words, said receiving station comprising: means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and means for equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 10
Dependent Claim
130 words
A time division multiple access (TDMA) communication receiving station for receiving a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a plurality of first predetermined synchronization words interleaved with a plurality of first data words, said receiving station comprising: means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and means for equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 11
Dependent Claim
134 words
An equalization circuit for reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a plurality of first predetermined synchronization words interleaved with a plurality of first data words, said equalization circuit comprising: means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and means for equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 12
Dependent Claim
134 words
An equalization circuit for reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a plurality of first predetermined synchronization words interleaved with a plurality of first data words, said equalization circuit comprising: means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and means for equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 13
Independent Claim
143 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: interleaving a plurality of first predetermined synchronization words with a plurality of first data words to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and equalizing the time delay spread characteristics of the first user message data word portions of said received TMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 14
Independent Claim
143 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: interleaving a plurality of first predetermined synchronization words with a plurality of first data words to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and equalizing the time delay spread characteristics of the first user message data word portions of said received TMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 15
Independent Claim
131 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a plurality of first predetermined synchronization words interleaved with a plurality of first data words, said method comprising the steps of: de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 16
Independent Claim
131 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a plurality of first predetermined synchronization words interleaved with a plurality of first data words, said method comprising the steps of: de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; and equalizing the time delay spread characteristics of the first user message data word portions of said received TDMA signal in response to said TDMA control signal at least the first time the plurality of predetermined synchronization word portions of said first user message are received.
Claim 17
Dependent Claim
149 words
A time division multiple access (TDMA) communication system comprising: a transmitting station including means for formatting a first predetermined synchronization word with a first data word to form a first user message; means for multiplexing said first user message with at least one other user message to form a TDMA signal; means for transmitting said TDMA signal; and a receiving station including means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal; thereby generating a TDMA control signal; means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and means for equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 18
Dependent Claim
149 words
A time division multiple access (TDMA) communication system comprising: a transmitting station including means for formatting a first predetermined synchronization word with a first data word to form a first user message; means for multiplexing said first user message with at least one other user message to form a TDMA signal; means for transmitting said TDMA signal; and a receiving station including means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal; thereby generating a TDMA control signal; means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and means for equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 19
Dependent Claim
37 words
The TDMA communication system according to claim 12, wherein said formatting means includes means for interleaving a plurality of said first predetermined synchronization words with segments of said first data word to form said first user message.
Claim 20
Dependent Claim
43 words
The TDMA communication system according to claim 13, wherein subsequent synchronization words of said plurality of first predetermined synchronization words are comprised of a fewer number of bits than said first predetermined synchronization word, said subsequent synchronization words functioning as sync update words.
Claim 21
Dependent Claim
29 words
The TDMA communication system according to claim 14, wherein said sync update words exhibit a word length of less than one-half of the length of said first synchronization word.
Claim 22
Dependent Claim
25 words
The TDMA communication system according to claim 14, wherein said interleaving means repetitively interleaves one of said sync update words at least every 0.3 milliseconds.
Claim 23
Dependent Claim
24 words
The TDMA communication system according to claim 12, wherein said TDMA signal is transmitted at a channel data rate of at least 250 kbps.
Claim 24
Dependent Claim
29 words
The TDMA communication system according to claim 12 wherein said receiving means includes coherent detection means for providing a first in-phase signal path and a second quadrature signal path.
Claim 25
Dependent Claim
19 words
The TDMA communication system according to claim 12, wherein said equalizing means is a complex signal decision feedback equalizer.
Claim 26
Dependent Claim
34 words
The TDMA communication system according to claim 12, said equalizing means is a digital signal processor having a maximum signal processing rate which is exceeded by the bit rate of said transmitted TDMA signal.
Claim 27
Dependent Claim
45 words
The TDMA communication system according to claim 12, wherein said equalizing means includes means for adapting the time delay spread parameters of said equalizing means in response to the reception of each of said first predetermined synchronization word portions of said de-multiplexed first user message.
Claim 28
Dependent Claim
38 words
The TDMA communication system according to claim 21, wherein said equalizing means performs both the adaptation and the equalization functions at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 29
Dependent Claim
135 words
A time division multiple access (TDMA) communication receiving station for receiving a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a first predetermined synchronization word formatted with a first data word, said receiving station comprising: means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and means for equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 30
Dependent Claim
135 words
A time division multiple access (TDMA) communication receiving station for receiving a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a first predetermined synchronization word formatted with a first data word, said receiving station comprising: means for receiving said transmitted TDMA signal; means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and means for equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 31
Dependent Claim
139 words
An equalization circuit for reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a first predetermined synchronization word formatted with a first data word, said equalization circuit comprising: means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and means for equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 32
Dependent Claim
139 words
An equalization circuit for reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a first predetermined synchronization word formatted with a first data word, said equalization circuit comprising: means for de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; means for storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and means for equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 33
Independent Claim
145 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: formatting a first predetermined synchronization word with a first data word to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user from said other user message of said received TDMA signal, thereby generating a TDMA control signal; storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 34
Independent Claim
145 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: formatting a first predetermined synchronization word with a first data word to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user from said other user message of said received TDMA signal, thereby generating a TDMA control signal; storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 35
Independent Claim
133 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a first predetermined synchronization word formatted with a first data word, said method comprising the steps of: de-multiplexing said first user from said other user message of said received TDMA signal, thereby generating a TDMA control signal; storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 36
Independent Claim
133 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication receiving station adapted to receive a transmitted TDMA signal having a first user message time-multiplexed with at least one other user message, said first user message having a first predetermined synchronization word formatted with a first data word, said method comprising the steps of: de-multiplexing said first user from said other user message of said received TDMA signal, thereby generating a TDMA control signal; storing the first user message portion of said received TDMA signal in response to said TDMA control signal; and equalizing the time delay spread characteristics of the data word portion of said stored user message at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 37
Independent Claim
154 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: interleaving a plurality of first predetermined synchronization words with a plurality of first data words to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; adapting the time delay spread parameters of an equalizing means in response to the reception of each of said first predetermined synchronization word portions of said de-multiplexed first user message; and equalizing the time delay spread characteristics of the first user message data word portion of said received TDMA signal in response to said TDMA control signal.
Claim 38
Independent Claim
154 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: interleaving a plurality of first predetermined synchronization words with a plurality of first data words to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user message from said other user message of said received TDMA signal, thereby generating a TDMA control signal; adapting the time delay spread parameters of an equalizing means in response to the reception of each of said first predetermined synchronization word portions of said de-multiplexed first user message; and equalizing the time delay spread characteristics of the first user message data word portion of said received TDMA signal in response to said TDMA control signal.
Claim 39
Independent Claim
182 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: formatting a first predetermined synchronization word with a first data word to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user from said other user message of said received TDMA signal, thereby generating a TDMA control signal; storing the first user message portion of said received TDMA signal in response to said TDMA control signal; adapting the time delay spread parameters of an equalizing means in response to the reception of each of said first predetermined synchronization word portions of said de-multiplexed first user message; and equalizing the time delay spread characteristics of the data word portion of said stored user message in response to said TDMA control signal at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
Claim 40
Independent Claim
182 words
A method of reducing the multipath interference distortion in a time division multiple access (TDMA) communication system comprising the steps of: formatting a first predetermined synchronization word with a first data word to form a first user message; multiplexing said first user message with at least one other user message to form a TDMA signal; transmitting said TDMA signal from a transmitting station; receiving said transmitted TDMA signal in a receiving station; de-multiplexing said first user from said other user message of said received TDMA signal, thereby generating a TDMA control signal; storing the first user message portion of said received TDMA signal in response to said TDMA control signal; adapting the time delay spread parameters of an equalizing means in response to the reception of each of said first predetermined synchronization word portions of said de-multiplexed first user message; and equalizing the time delay spread characteristics of the data word portion of said stored user message in response to said TDMA control signal at least during the time subsequent to receiving said first user message portion of said transmitted TDMA signal.
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USPTO Annuity & Maintenance Windows
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|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |