US6678314B2
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Spreading factor determination
Assignee: Nokia Oyj
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Filing: 2001-08-29
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Granted: 2004-01-13
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Expires: 2021-08-29
Abstract
Abstract The present invention relates to a method and circuitry for determining a spreading factor in a communication system with variable data rates. In such a system the received signal may include a plurality of data symbols that are spread in the transmission signal in a manner that is defined by a spreading code and a spreading factor, the spreading factor being one of a plurality of possible spreading factors. In accordance with the method, the received signal is processed so as to produce signal outputs which are cleared from the effects of the spreading code, autocorrelation values are computed for the signal outputs, and the spreading factor is determined based on the computed autocorrelation values.
Inventors
- 👤 Markku Juntti
- 👤 Kari Pajukoski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:02
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707; H04J; H04J13/00; H04J13/0007; H04J13/004; H04J13/0044
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
107 words
A method for determining a spreading factor for a received signal in a communication system with variable data transmission rates, wherein the received signal includes a plurality of data symbols that are spread in the received signal in a manner defined by a spreading code and a spreading factor, the spreading factor being one of a plurality of possible spreading factors, comprising: processing the received signal so as to produce signal outputs which are cleared from the effects of the spreading code; computing autocorrelation values for the signal outputs; and determining the spreading factor that was used for the received signal based on the computed autocorrelation values.
Claim 2
Independent Claim
107 words
A method for determining a spreading factor for a received signal in a communication system with variable data transmission rates, wherein the received signal includes a plurality of data symbols that are spread in the received signal in a manner defined by a spreading code and a spreading factor, the spreading factor being one of a plurality of possible spreading factors, comprising: processing the received signal so as to produce signal outputs which are cleared from the effects of the spreading code; computing autocorrelation values for the signal outputs; and determining the spreading factor that was used for the received signal based on the computed autocorrelation values.
Claim 3
Dependent Claim
33 words
A method according to claim 1 , wherein the smallest possible spreading factor of the plurality of spreading factors is employed when processing the signal to clear the effects of the spreading code.
Claim 4
Dependent Claim
48 words
A method according to claim 1 , wherein the processing comprises correlation of the signal by despreading the signal based on at least one spreading factor of the plurality of possible spreading factors and downsampling the signal based on the spreading code to an assumed data symbol rate.
Claim 5
Dependent Claim
17 words
A method according to claim 3 , wherein the signal is correlated with each possible spreading factor.
Claim 6
Dependent Claim
22 words
A method according to claim 3 , wherein a maximal ratio combination signal is correlated with the at least one spreading factor.
Claim 7
Dependent Claim
21 words
A method according to claim 3 , comprising the step of changing the spreading factor that is used for the correlation.
Claim 8
Dependent Claim
30 words
A method according to claim 1 , wherein the processing comprises filtering the signal by a matched filter and sampling the signal to at least one different data symbol rate.
Claim 9
Dependent Claim
20 words
A method according to claim 1 , wherein the data symbols are spread in a plurality of subsequent data frames.
Claim 10
Dependent Claim
36 words
A method according to claim 1 , wherein a proportion of the smallest possible spreading factor of the plurality of spreading factors is employed when processing the signal to clear the effects of the spreading code.
Claim 11
Dependent Claim
48 words
A method according to claim 1 , wherein the processing comprises correlating the signal by despreading the signal based on a proportion of each possible spreading factor of the plurality of spreading factors and downsampling the signal based on the spreading code to an assumed data symbol rate.
Claim 12
Dependent Claim
23 words
A method according to claim 9 , wherein the proportion is obtained by dividing the spreading factor by a square root of 2.
Claim 13
Dependent Claim
24 words
A method according to claim 9 , comprising correlating a maximal ratio combination signal based on the proportion of the smallest possible spreading factor.
Claim 14
Dependent Claim
30 words
A method according to claim 3 , wherein the correlation is based on a possible spreading factor and the determination of the spreading factor is based on several autocorrelation stages.
Claim 15
Dependent Claim
30 words
A method according to claim 3 , wherein the computing of the autocorrelation values comprises computing of an one-step autocorrelation function for each correlator output of a dedicated data channel.
Claim 16
Dependent Claim
23 words
A method according to claim 3 , wherein the spreading factor is determined by selecting the highest value of the computed autocorrelation values.
Claim 17
Dependent Claim
25 words
A method according to claim 3 , comprising computing the correlation for a predefined time slot and averaging the results for the predefined time slot.
Claim 18
Dependent Claim
44 words
A method according to claim 1 , wherein an autocorrelation vector is computed for a predefined delay from each correlated data symbol, a decision metric vector is determined from the autocorrelation vector and the spreading factor is determined based on the decision metric vector.
Claim 19
Dependent Claim
33 words
A method according to claim 17 , wherein the spreading factor is determined based on determination of an element of the subsequent elements of the decision metric vector that has the maximum value.
Claim 20
Dependent Claim
39 words
A method for channel estimation in a communication system that is based on direct sequence spread spectrum technique wherein the data symbol rate estimate is based on a spreading factor that is determined in accordance with claim 1 .
Claim 21
Dependent Claim
29 words
A method according to claim 19 , wherein the channel estimation is based both on a data rate information received from a transmitting station and the determined spreading factor.
Claim 22
Dependent Claim
42 words
A method for signal-to-interference ratio estimation in a data channel of communication system that is based on direct sequence spread spectrum technique wherein the signal-to-interference ratio estimation is based on a spreading factor that is determined in accordance with claim 1 .
Claim 23
Dependent Claim
32 words
A method according to claim 1 , comprising determining the spreading factor in more than one stage, wherein at least two different spreading factor determination methods are employed in the different stages.
Claim 24
Dependent Claim
76 words
A method for determining a spreading factor for a signal in a communication system with variable data transmission rates, wherein the received signal includes a plurality of data symbols that are spread in the signal in a manner defined by a spreading code and a spreading factor, the spreading factor being one of a plurality of possible spreading factors, comprising at least two stages, wherein one of the stages is as claimed in claim 1 .
Claim 25
Dependent Claim
112 words
A circuitry for determining a spreading factor for a received signal in a communication system with variable data transmission rates, wherein the received signal includes a plurality of data symbols that are spread in the received signal in a manner defined by a spreading code and a spreading factor, the spreading factor being one of a plurality of possible spreading factors, comprising: means for processing the received signal so as to produce signal outputs which are cleared from the effects of the spreading code; means for computing autocorrelation values for the signal outputs; and means determining the spreading factor that was used for the received signal based on the computed autocorrelation values.
Claim 26
Dependent Claim
112 words
A circuitry for determining a spreading factor for a received signal in a communication system with variable data transmission rates, wherein the received signal includes a plurality of data symbols that are spread in the received signal in a manner defined by a spreading code and a spreading factor, the spreading factor being one of a plurality of possible spreading factors, comprising: means for processing the received signal so as to produce signal outputs which are cleared from the effects of the spreading code; means for computing autocorrelation values for the signal outputs; and means determining the spreading factor that was used for the received signal based on the computed autocorrelation values.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2007-01-12 | 2007-07-14 | 2008-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-01-12 | 2011-07-14 | 2012-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-01-12 | 2015-07-14 | 2016-01-13 | $7700.00 | Window Closed / Lapsed |