EP1014107A2
Expired / Lapsed
EP
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Mobile speed estimation for digital cellular radio systems
Assignee: Nortel Networks Ltd
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Filing: 1999-12-15
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Granted: —
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Expires: 2019-12-15
Abstract
Abstract For a hierarchical mobile cellular communications system (102, 106) comprising a plurality of microcells (102) and overlaid macrocells (108), a method is disclosed for estimating the speed of a mobile (C, P). The speed estimate assists in the assignment of slow-moving mobiles to microcells and fast-moving mobiles to macrocells, thus keeping the cellular system in optimum utilization. The method first calculates a power signal (604, 704) of the received signals (602, 702). The power signal is then filtered (606) and decimated (608). The speed of a mobile is estimated from a determination (610) of the offset autocorrelation of the filtered and decimated power signal.
Inventors
- 👤 Chengshan Xiao
- 👤 Karl D. Mann
- 👤 Jan C. Oliver
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 13:47
CPC Classifications
G; G01; G01S; G01S11/00; G01S11/02; G01S11/10; G01S11/06; H; H04; H04W; H04W36/00; H04W36/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
70 words
A method for estimating a speed of a mobile
communication apparatus in a mobile communication network
comprising: receiving samples of a signal from said mobile
communication apparatus; deriving a power signal from said samples; and
estimating an offset autocorrelation value of said
power signal by correlating said power signal with a
version of itself offset in time, said offset
autocorrelation value representative of said speed
of said mobile communication apparatus.
Claim 2
Dependent Claim
24 words
The method of claim 1, further comprising filtering
said power signal to limit noise and interference prior
to said estimating said offset autocorrelation value.
Claim 3
Dependent Claim
26 words
The method of claim 1 or 2, further comprising
decimating said filtered power signal to reduce
computational complexity, prior to said estimating said
offset autocorrelation value.
Claim 4
Independent Claim
75 words
The method of any preceding claim, wherein said
samples are arranged in time slots and wherein said
estimating said offset autocorrelation value comprises, for each of a plurality of time slots,
estimating a single time slot offset autocorrelation
value by correlating said power signal with a
version of said power signal displaced by a
predetermined number of time slots; and summing each said single time slot offset
autocorrelation value to estimate said offset
autocorrelation value.
Claim 5
Dependent Claim
49 words
The method of claim 4, wherein estimating each said
single time slot offset autocorrelation value comprises,
repetitively, multiplying a sample of said power signal from
a given time slot with a corresponding sample of
said power signal displaced by said predetermined
number of time slots; and summing resultant products.
Claim 6
Independent Claim
41 words
The method of any preceding claim, further
comprising: comparing said offset autocorrelation value to
a first threshold after normalization; and if said offset autocorrelation value is less
than said first threshold, indicating said speed of
said mobile communication apparatus as "fast."
Claim 7
Dependent Claim
28 words
The method of claim 6, further comprising, if said
offset autocorrelation value is greater than said first
threshold, indicating said speed of said mobile
communication apparatus as "slow."
Claim 8
Dependent Claim
38 words
The method of claim 6, further comprising: comparing said offset autocorrelation value to
a second threshold; and if said offset autocorrelation value is greater
than said second threshold, indicating said speed of
said mobile communication apparatus as "slow."
Claim 9
Dependent Claim
34 words
The method of claim 8, further comprising, if said
offset autocorrelation value is greater than said first
threshold and less than said second threshold, indicating
said speed of said mobile communication apparatus as
"indeterminate."
Claim 10
Independent Claim
20 words
The method of any preceding claim, wherein said
estimating comprises determining a time-limited offset
correlation value of said power signal.
Claim 11
Dependent Claim
52 words
A speed estimation apparatus comprising: a receiver for receiving samples of a signal
from a mobile communication apparatus; means for deriving a power signal from said
samples; and means for estimating an offset autocorrelation
value of said power signal, said offset
autocorrelation value representative of said speed
of said mobile communication apparatus.
Claim 12
Dependent Claim
28 words
A computer program element comprising computer
program code means to make processor-controlled apparatus
execute procedure to perform the method steps of any one
of claims 1 to 10.
Claim 13
Dependent Claim
15 words
The computer program element as claimed in claim 12,
embodied in a computer readable medium.
References Cited (Backward Citations)
No citation records indexed.
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