Rake receiver with multi-path interference accommodation
View Patent ↗A method of extracting data from a received signal including multi-path interference in a rake receiver. The method includes sampling and filtering the received signal; estimating a time delay τ l between paths for the filtered samples ψ(τ); and estimating channel complex coefficient c l for the filtered samples ψ(τ). Transmitted data x(τ l ) is extracted from the filtered samples ψ(τ) for each path l by solutions of simultaneous equations of the following filtered samples ψ(τ) equation ψ ( τ ) R ff - 1 ( τ k - τ ^ 0 ) Λ ss H ( τ ^ k ) = ∑ l = 0 N p + 1 c i ( τ l ) × ( τ l ) Λ ss ( τ l ) R ff ( τ l - τ ^ 0 ) R ff - 1 ( τ k - τ ^ 0 ) Λ ss H ( τ ^ k ) + ( τ ) wherein k is a particular path, N p is the number of visible paths, R ƒƒ (τ l –τ o ) is a double convolution matrix of the filtering process and R ƒƒ −1 (τ k −– o ) is the pseudo inverse, Λ ss (τ l ) is the product of spreading and scrambling matrices and Λ ss H (τ k ) is the inverse, and (τ) is noise.
1. A method of extracting data from a received signal including multi-path interference in a rake receiver, comprising:
sampling and filtering the received signal;
estimating a time delay τ l between paths for the filtered samples ψ(τ);
estimating channel complex coefficient c l for the filtered samples ψ(τ);
extracting transmitted data x(τ l ) from the filtered samplesψ(τ) for each path l by solutions of simultaneous equations of the following filtered samples ψ(τ) equation
ψ
(
τ
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R
ff
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Λ
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x
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Λ
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wherein k is a particular path, N p the number of visible paths, R ƒƒ (τ l –τ o ) is a double convolution matrix of the filtering process and R ƒƒ −1 (τ o –τ o ) is the pseudo inverse, Λ ss (τ l ) is the product of spreading and scrambling matrices and Λ ss H (τ o –τ o ) is the inverse, and (τ) is noise.
2. The method according to claim 1 , wherein the method is selectively performed for estimated time delay τ l of a duration of one chip or less of the receiver.
3. The method according to claim 1 , wherein the filtered samples ψ(τ) equations without the noises (τ) are solved.
4. The method according to claim 1 , wherein the number of solutions is less than or equal to the number of over-samples per chip of the receiver.
5. The method according to claim 1 , wherein the solutions of the simultaneous equations are stored in the receiver and the method is performed in software.
6. The method according to claim 5 , wherein the number of stored solutions is less than or equal to the number of over-samples per chip of the receiver.