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US5745485A
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Dual code multiple access for wireless data networks
Assignee: ALOHA Networks Inc
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Filing: 1996-06-19
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Granted: 1998-04-28
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Expires: 2016-06-19
Abstract
Abstract A simplified process of signal detection in a multiple access data communications uses a small number of different spreading signals rather than a single spreading signal such as used in a Spread ALOHA multiple access network. The process selects a spreading signal which depends upon a property of the signal being transmitted rather than upon the transmitter which is transmitting the signal as in Code Division Multiple Access (CDMA). Multiple transmitters can use pilot signals and transmit the multiple data signal with the selected spreading sequences. The hub station receives the multiple data signals and detects the multiple data signals with matched filters or correlators matched to the code spreading sequences. Outputs of the matched filters or correlators can create control signals for offsetting the transmitted data signals by advancing or retarding timing of the transmitting of the multiple data signals from the multiple transmitters. The spreading signal for each transmitter may also depend upon whether the transmission is on the "in phase" channel or the "quadrature" channel, thus doubling the number of spreading codes used in the data network. The codes selected for spreading in such a dual code (or multiple code) Spread ALOHA network can be different "m-sequences" for each class of traffic.
Inventors
- 👤 Norman Abramson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:23
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2628; H04B7/264
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
152 words
A method of providing multiple access to a data communications channel, comprising forming multiple data signals with a first identical code spreading sequence and a second code spreading sequence in multiple transmitters, transmitting the multiple data signals from the multiple transmitters, detecting the multiple signals with matched filters or correlator or a multiplicity of matched filters or correlators matched to the first and second code spreading sequences in a hub station, using an output of the matched filters in the hub station for respectively offsetting the transmitted data signals by retarding and advancing some of the transmitted data signals, and transmitting control signals from the hub station to the transmitters for respectively advancing or retarding timing of some of the multiple transmitters for offsetting the transmitted data signals from the transmitters using the first or second identical code spreading sequence for receiving at the hub station data signals offset from each other.
Claim 2
Independent Claim
152 words
A method of providing multiple access to a data communications channel, comprising forming multiple data signals with a first identical code spreading sequence and a second code spreading sequence in multiple transmitters, transmitting the multiple data signals from the multiple transmitters, detecting the multiple signals with matched filters or correlator or a multiplicity of matched filters or correlators matched to the first and second code spreading sequences in a hub station, using an output of the matched filters in the hub station for respectively offsetting the transmitted data signals by retarding and advancing some of the transmitted data signals, and transmitting control signals from the hub station to the transmitters for respectively advancing or retarding timing of some of the multiple transmitters for offsetting the transmitted data signals from the transmitters using the first or second identical code spreading sequence for receiving at the hub station data signals offset from each other.
Claim 3
Dependent Claim
21 words
The method of claim 1, further comprising selecting the code spreading sequences according to different kinds of multiple data signals traffic.
Claim 4
Dependent Claim
16 words
The method of claim 1, wherein the transmitting comprises transmitting multiple signals on a channel medium.
Claim 5
Dependent Claim
20 words
The method of claim 1, further comprising selecting two codes rather than one code for each kind of data signal.
Claim 6
Independent Claim
200 words
A method of simplifying a process of signal detection in a multiple access data communications channel, comprising broadcasting first and second pilot signals from a hub station, selecting between first and second code spreading sequences according to data traffic, controlling multiple data signals using the first or second code spreading sequence from multiple transmitters with the pilot signals, transmitting the multiple data signals and selected spreading sequences from the multiple transmitters, receiving the multiple data signals at the hub station, detecting the multiple data signals with matched filters or correlators matched to the code spreading sequences at the hub station, using an output of the matched filters or correlators matched to the code spreading sequences in the hub station for creating control signals for offsetting the transmitted data signals by advancing or retarding timing of the transmitting of the multiple data signals from the multiple transmitters, broadcasting the control signals to the multiple transmitters, and receiving the offset transmitted data signals using identical code spreading sequences from the transmitters at the hub station with the data signals offset from each other by a different number of chip times, thus decreasing the interference of signals from different transmitters with each other.
Claim 7
Independent Claim
200 words
A method of simplifying a process of signal detection in a multiple access data communications channel, comprising broadcasting first and second pilot signals from a hub station, selecting between first and second code spreading sequences according to data traffic, controlling multiple data signals using the first or second code spreading sequence from multiple transmitters with the pilot signals, transmitting the multiple data signals and selected spreading sequences from the multiple transmitters, receiving the multiple data signals at the hub station, detecting the multiple data signals with matched filters or correlators matched to the code spreading sequences at the hub station, using an output of the matched filters or correlators matched to the code spreading sequences in the hub station for creating control signals for offsetting the transmitted data signals by advancing or retarding timing of the transmitting of the multiple data signals from the multiple transmitters, broadcasting the control signals to the multiple transmitters, and receiving the offset transmitted data signals using identical code spreading sequences from the transmitters at the hub station with the data signals offset from each other by a different number of chip times, thus decreasing the interference of signals from different transmitters with each other.
Claim 8
Dependent Claim
35 words
The method of claim 5, further comprising selecting two codes rather than one code according to the data traffic and using a pair of codes rather than just one code for spreading the transmitted signal.
Claim 9
Dependent Claim
68 words
The method of claim 5, further comprising subtracting successive signals from the received signals for allowing easier detecting of other signals contained in the received signals, reconstructing an interference pattern and subtracting the pattern at the output of a matched filter or correlator matched to a single code spreading sequence, and detecting the multiple signals in a single multiple access channel in the presence of mutual signal interference.
Claim 10
Independent Claim
132 words
A method of providing multiple access to a data communications channel, comprising selecting a code spreading sequence from multiple code spreading sequences according to a type of transaction, digital voice or files in multiple data signals, using multiple code spreading sequences in creating multiple signals in each of multiple transmitters, transmitting the multiple signals from the multiple transmitters in a multiple access channel, receiving the multiple signals at a hub station, and detecting the multiple signals by using matched filters or correlators matched to the code spreading sequence in the hub station, subtracting successive signals in the multiple access channel from the received signals for allowing easier detecting of other signals contained in the received signals, and detecting the multiple signals in the multiple access channel in the presence of mutual interference.
Claim 11
Independent Claim
132 words
A method of providing multiple access to a data communications channel, comprising selecting a code spreading sequence from multiple code spreading sequences according to a type of transaction, digital voice or files in multiple data signals, using multiple code spreading sequences in creating multiple signals in each of multiple transmitters, transmitting the multiple signals from the multiple transmitters in a multiple access channel, receiving the multiple signals at a hub station, and detecting the multiple signals by using matched filters or correlators matched to the code spreading sequence in the hub station, subtracting successive signals in the multiple access channel from the received signals for allowing easier detecting of other signals contained in the received signals, and detecting the multiple signals in the multiple access channel in the presence of mutual interference.
Claim 12
Dependent Claim
60 words
The method of claim 8, further comprising selecting the multiple code spreading sequence for all of the transmitters from a specific class of maximum length shift register (MLSR) sequence or m-sequence codes in a length equal to 2 n -1 for integer values of n, and producing reduced interference as compared with interference produced using a code selected at random.
Claim 13
Dependent Claim
113 words
The method of claim 8, wherein the subtracting further comprises determining a strongest or earliest signal to arrive at the hub station and then subtracting the first signal from the multiple signals at an output of a matched filter or correlator matched to a single code spreading sequence, examining remaining signals after subtracting the first signal, detecting a next signal, subtracting the next signal, and repeating the determining, subtracting and detecting as long as a new remaining signal is picked out of the multiple access channel, where each of the separate signals in the multiple access channel is spread by one of the multiple code spreading sequences according to the data signal type.
Claim 14
Dependent Claim
16 words
The method of claim 8, wherein the transmitting comprises transmitting multiple signals on a channel medium.
Claim 15
Dependent Claim
20 words
The method of claim 8, further comprising selecting two codes rather than one code for each kind of data signal.
Claim 16
Independent Claim
151 words
A method of providing a multiple access data communications channel, comprising selecting according to traffic one of plural common code spreading sequences for all transmitters from a specific class of maximum length shift register (MLSR) sequence or m-sequence codes in a length equal to 2 n -1 for integer values of n, using the selected code spreading sequences in multiple transmitters creating multiple data signals with identical code spreading sequences in the multiple transmitters, transmitting the multiple data signals from the multiple transmitters, detecting the multiple data signals with matched filters or correlators matched to single code spreading sequences in a hub station, using signals at a matched filter or correlator matched to a single code spreading sequence in the hub station for separating the multiple data signals, and producing reduced mutual signal interference as compared with mutual signal interference produced by selecting a code in a random or pseudorandom manner.
Claim 17
Independent Claim
151 words
A method of providing a multiple access data communications channel, comprising selecting according to traffic one of plural common code spreading sequences for all transmitters from a specific class of maximum length shift register (MLSR) sequence or m-sequence codes in a length equal to 2 n -1 for integer values of n, using the selected code spreading sequences in multiple transmitters creating multiple data signals with identical code spreading sequences in the multiple transmitters, transmitting the multiple data signals from the multiple transmitters, detecting the multiple data signals with matched filters or correlators matched to single code spreading sequences in a hub station, using signals at a matched filter or correlator matched to a single code spreading sequence in the hub station for separating the multiple data signals, and producing reduced mutual signal interference as compared with mutual signal interference produced by selecting a code in a random or pseudorandom manner.
Claim 18
Dependent Claim
20 words
The method of claim 13, further comprising selecting two codes rather than one code for each kind of data signal.
Claim 19
Dependent Claim
16 words
The method of claim 13, wherein the transmitting comprises transmitting multiple signals on a channel medium.
Claim 20
Dependent Claim
21 words
The method of claim 2, wherein the multiple data signals are selected from a group comprising transactions, digital voice and files.
Claim 21
Dependent Claim
30 words
The method of claim 3, wherein the channel medium is selected from a group comprising packet radio channels, microwave channels, fiber optic channels, satellite channels, cellular systems, cables and wires.
Claim 22
Dependent Claim
41 words
The method of claim 4, wherein the data signal comprises an in-phase portion and a quadrature portion, and further comprising applying one of the two codes selected for the in-phase portion and another of the two codes for the quadrature portion.
Claim 23
Dependent Claim
41 words
The method of claim 6, wherein the data signal comprises an in-phase portion and a quadrature portion, and further comprising applying one of the two codes selected for the in-phase portion and another of the two codes for the quadrature portion.
Claim 24
Dependent Claim
30 words
The method of claim 11, wherein the channel medium is selected from a group comprising packet radio channels, microwave channels, fiber optic channels, satellite channels, cellular systems, cables and wires.
Claim 25
Dependent Claim
41 words
The method of claim 12, wherein the data signal comprises an in-phase portion and a quadrature portion, and further comprising applying one of the two codes selected for the in-phase portion and another of the two codes for the quadrature portion.
Claim 26
Dependent Claim
41 words
The method of claim 14, wherein the data signal comprises an in-phase portion and a quadrature portion, and further comprising applying one of the two codes selected for the in-phase portion and another of the two codes for the quadrature portion.
Claim 27
Dependent Claim
30 words
The method of claim 15, wherein the channel medium is selected from a group comprising packet radio channels, microwave channels, fiber optic channels, satellite channels, cellular systems, cables and wires.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-04-27 | 2001-10-27 | 2002-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-27 | 2005-10-27 | 2006-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-27 | 2009-10-27 | 2010-04-28 | $7700.00 | Window Closed / Lapsed |