Method for detecting a signal and receiver system for the implementation of the method
View Patent ↗The method seeks a high-performance detection of a signal burst transmitted on the initiative of a sender on a radio channel listened to by a receiver system. The transmitted burst represents a predetermined digital sequence, serving for example to request access to a radio system or to ensure the synchronization of a radio interface. Channel parameters representing a statistical behavior of the radio channel are estimated and a detection magnitude is evaluated on the basis of the estimated channel parameters and of a correlation between a signal received at the receiver system and the predetermined digital sequence. The estimated channel parameters comprise moments of order greater than 2 of the gain on the radio channel.
1. A method for detecting a signal burst transmitted on the initiative of a sender on a radio channel listened to by a receiver system, the transmitted burst representing a predetermined digital sequence, in which method channel parameters representing a statistical behavior of the radio channel are estimated and a signal burst detection magnitude is evaluated on the basis of the estimated channel parameters and of a correlation between said signal burst as received at the receiver system and the predetermined digital sequence, wherein said estimated channel parameters comprise moments of order greater than 2 of the gain on the radio channel.
2. The method as claimed in claim 1 , in which the signal received is subjected to a filtering matched to the predetermined digital sequence so as to obtain said correlation in the form of a complex signal having a first component on an in-phase path and a second component on a quadrature path.
3. The method as claimed in claim 2 , in which the evaluated detection magnitude is proportional to
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where No denotes the estimated power of the noise on the radio channel, z x and z y denote said first and second components, ma x,n and ma y,n denote the moments of order n of the gain on the in-phase path and on the quadrature path respectively, H n denotes the Hermite polynomial of order n and k is an integer larger than 2.
4. The method as claimed in claim 1 , in which said sender is a mobile terminal, said receiver system belongs to a radiocommunication network and in which said burst is sent so as to request access to the network.
5. The method as claimed in claim 1 , in which said sender comprises a base station of a radiocommunication network, said receiver system forms part of a mobile terminal, and in which said burst is sent for the temporal synchronization between the sender and the receiver system.
6. The method as claimed in claim 1 , in which the detection of the burst is utilized to select fingers of a rake receiver.
7. The method as claimed in claim 1 , in which the burst belongs to a radio signal sequence sent periodically, and in which said moments are estimated over a duration covering several periods of said radio signal sequence.
8. A radio receiver system capable of detecting a signal burst transmitted on the initiative of a sender on a radio channel listened to by the receiver system, the transmitted burst representing a predetermined digital sequence, the receiver system comprising means for estimating channel parameters representing a statistical behavior of the radio channel and means for evaluating a signal burst detection magnitude on the basis of the estimated channel parameters and of a correlation between said signal burst as received at the receiver system and the predetermined digital sequence, wherein said estimated channel parameters comprise moments of order greater than 2 of the gain on the radio channel.
9. A radio receiver system as claimed in claim 8 , further comprising means for subjecting the received signal to a filtering matched to the predetermined digital sequence so asto obtain said correlation in the form of a complex signal having a first component on an in-phase path and a second component on a quadrature path.
10. A radio receiver system as claimed in claim 9 , in which the evaluated detection magnitude is proportional to
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∑
n
=
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k
1
n
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(
N
0
)
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·
H
n
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z
x
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0
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·
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x
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n
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·
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=
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1
n
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z
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where N 0 estimated power of the noise on the radio channel z x and z y denote said first and second components, ma x,n and ma y,n denote the moments of order n of the gain on the in-phase path and on the quadrature path respectively, H n denotes the Hermite polynomial of order n and k is an integer larger than 2.
11. A radio receiver system as claimed in claim 8 , belonging to a radiocommunication network, said sender being a mobile terminal, and said burst being sent so as to request access to the network.
12. A radio receiver system as claimed in claim 8 , forming part of a mobile terminal, said sender comprising a base station of a radiocommunication network, and said burst being sent for the temporal synchronization between the sender and the receiver system.
13. A radio receiver system as claimed in claim 8 , further comprising means for utilizing the detection of the burst to select fingers of a rake receiver.
14. radio receiver system as claimed in claim 8 , in which the burst belongs to a radio signal sequence sent periodically, and in which said moments are estimated over a duration covering several periods of said radio signal sequence.