Patent US3634628A successfully refreshed from Google Patents.
US3634628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for forming tdm signal bursts for a time division multiple access satellite communication system
Assignee: International Telecommunications Satellite Organization
•
Filing: 1970-01-13
•
Granted: 1972-01-11
•
Expires: 1990-01-13
Abstract
Abstract A method and apparatus by which active information channels are sampled at each station so that information bursts are formed directly by the sampler, thereby eliminating the need for a timecompressing memory to form the bursts. The active channels at each station are sampled at the proper time to reach the satellite in the TDM time slot assigned to the station. The sampling period is the Nyquist period and is equal to the satellite TDM frame time. The sampling period is divided into equal intervals identical in number to the total number of channels in the system so that there is one channel in each interval. Consequently, the burst from the sampler of each station has a burst length or occurs in the period NT where y is the number of active channels at the station, N is the total number of channels in the system, and T is the Nyquist sampling period, which is 125 microseconds for voice intelligence. Channels may be added to a station''s transmission burst by activating these channels at the sampler, thereby increasing the length of the burst to accommodate the added channels. The burst length is shortened if channels are dropped.
Inventors
- 👤 Tadahiro Sekimoto
- 👤 Ova G Gabbard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:45
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/204; H04B7/212; H04B7/2121; H04B7/2123
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
129 words
An improved method of directly forming a time division multiplex (TDM) signal burst at a transmitting station in a time division multiple access (TDMA) communication system including a plurality of transmitting stations and a single relay station wherein said transmitting station has a plurality of channels and normally places a TDM burst in an assigned time slot of a TDM frame at the relay station, said burst containing samples of information from the channels at said transmitting station and said TDM frame containing no more than one burst from each transmitting station, comprising sampling the channels at said station during a time period no longer than said assigned time slot and at a constant rate such that only one sample from each channel is formed during the TDM frame.
Claim 2
Dependent Claim
129 words
An improved method of directly forming a time division multiplex (TDM) signal burst at a transmitting station in a time division multiple access (TDMA) communication system including a plurality of transmitting stations and a single relay station wherein said transmitting station has a plurality of channels and normally places a TDM burst in an assigned time slot of a TDM frame at the relay station, said burst containing samples of information from the channels at said transmitting station and said TDM frame containing no more than one burst from each transmitting station, comprising sampling the channels at said station during a time period no longer than said assigned time slot and at a constant rate such that only one sample from each channel is formed during the TDM frame.
Claim 3
Dependent Claim
60 words
An improved method of forming a TDM signal burst as defined in claim 1 wherein the channels having information are designated as active channels while the remaining channels are designated as inactive channels comprising sampling only the active channels at said station, whEreby the TDM burst length is varied in proportion to the number of active channels at said station.
Claim 4
Dependent Claim
66 words
An improved method of forming a TDM signal burst as defined in claim 1 wherein the channels having information are designated as active channels while the remaining channels are designated as inactive channels and only the active channels of said station are sampled and the active channel bursts are pulse amplitude modulated and further comprising encoding said active channel sample bursts into pulse code modulation bursts.
Claim 5
Dependent Claim
35 words
An improved method of forming a TDM signal burst as defined in claim 1 further comprising beginning the sampling at said station at the time for initiation of transmission of a burst by said station.
Claim 6
Dependent Claim
35 words
An improved method of forming a TDM signal burst as defined in claim 1 further comprising setting said sampling rate of each channel equal to the Nyquist frequency of the information contained in said channels.
Claim 7
Dependent Claim
33 words
An improved method of forming a TDM signal burst as defined in claim 4 further comprising setting said sampling rate equal to the Nyquist frequency of the information contained in said active channels.
Claim 8
Dependent Claim
35 words
An improved method of forming a TDM signal burst as defined in claim 6 wherein the information is voice, the sampling rate is 8,000 cycles per second, and the TDM frame time is 125 microseconds.
Claim 9
Dependent Claim
42 words
An improved method of forming a TDM signal burst as defined in claim 1 comprising varying the burst length to make it proportional to the number of active channels at said station, thereby correspondingly varying the time slot assigned to said station.
Claim 10
Dependent Claim
37 words
An improved method of forming a TDM signal burst as defined in claim 1 wherein the active channel bursts are pulse amplitude modulated and further comprising encoding said active channel sample bursts into pulse code modulation bursts.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |