Receiver for a digital transmission system

Claim 2

A receiver for data transmitted over a transmission channel in which data as transmitted contain a transmitted training data sequence (X), wherein the receiver comprises means for receiving data including data symbols (b') and a received training data sequence (X'), means for storing a copy of said transmitted training data sequence, and means for estimating a channel impulse response (H(0)) for said transmission channel based on said received training data sequence, characterized in that said means for estimating comprises: means for determining an estimated sequence (Y) based on the estimated channel impulse response and said copy of the transmitted training data sequence, and means for determining a degree of match of said estimated sequence with said received training data sequence.

Claim 3

A receiver as claimed in claim 1, characterized in that said means for determining an estimated sequence (Y) folds said copy of the transmitted training data sequence with the estimated channel impulse response.

Claim 4

A receiver as claimed in claim 2, characterized in that for the degree of match an estimate (S) is formed which describes the receiving quality.

Claim 5

A receiver as claimed in claim 3, characterized in that the estimate (S) is formed from a sum of the squared differences between corresponding elements of the estimated sequence (Y) and the received training data sequence (X').

Claim 6

A receiver as claimed in claim 4, characterized in that for the formation of the squared differences a number of elements are taken from the middle of the estimated and the received training data sequences (Y, X').

Claim 7

A receiver as claimed in claim 5, characterized in that the receiver comprises at least two receive loops (A, B), means for sampling one of said loops to provide sample values (Z a , Z b ), means for calculating estimation criteria (S a , S b ) characteristic of the receiving quality, and means, responsive to said estimation criteria, for selecting said sample values of one of said receive loops for further signal processing.

Claim 8

A receiver as claimed in claim 1, characterized in that said means for determining a degree of match provides an estimate (S) which describes receiving quality.

Claim 9

A receiver as claimed in claim 7, characterized in that said means for estimating further comprises means for determining an energy content of said received training data sequence, said energy content being based on a summation of squared values of individual elements X' i of said received training data sequence (X'); and said estimate (S) is weighted in accordance with said energy content.

Claim 10

A receiver as claimed in claim 7, comprising means for detecting said data symbols (b'), characterized in that the receiver comprises means for forming reliability information for said detected data symbols weighted by said estimate (S).

Claim 11

A receiver as claimed in claim 9, comprising a program-controlled processor, characterized in that said estimate (S) is determined by said processor.

Claim 12

A receiver as claimed in claim 10, characterized in that said processor is a signal processor, and said means for estimating and said means for determining an estimated sequence form part of said signal processor.

Claim 13

A receiver as claimed in claim 7, comprising means for detecting said data symbols (b'), characterized in that the receiver comprises means for determining a quality factor Q based on energy content of said received training data sequence (X'), divided by said estimate (S).

Claim 14

A receiver as claimed in claim 12, comprising a program-controlled processor, characterized in that said estimate (S) is determined by said processor.

Claim 15

A receiver as claimed in claim 13, characterized in that said processor is a signal processor, and said means for estimating and said means for determining an estimated sequence form part of said signal processor.

Claim 16

A receiver as claimed in claim 1, characterized in that the receiver comprises at least two receive loops (A, B), means for sampling one of said loops to provide sample values (Z a , Z b ), means for calculating estimation criteria (S a , S b ) characteristic of the receiving quality, and means, responsive to said estimation criteria, for selecting said sample values of one of said receive loops for further signal processing.

Claim 17

A receiver for data transmitted over a transmission channel in which data as transmitted contain a transmitted training data sequence (X), wherein the receiver comprises means for receiving data including data symbols (b') and a received training data sequence (X'), means for storing a copy of said transmitted training data sequence, and means for estimating a channel impulse response (H(0)) for said transmission channel based on said received training data sequence, characterized in that said means for estimating comprises: means for determining an estimated sequence (Y) based on the estimated channel impulse response and said copy of the transmitted training data sequence, and means for forming a sum of squared differences between corresponding elements of said estimated sequence and said received training data sequence, and determining a degree of match of said estimated sequence with said received training data sequence based on said sum.

Claim 18

A receiver for data transmitted over a transmission channel in which data as transmitted contain a transmitted training data sequence (X), wherein the receiver comprises means for receiving data including data symbols (b') and a received training data sequence (X'), means for storing a copy of said transmitted training data sequence, and means for estimating a channel impulse response (H(0)) for said transmission channel based on said received training data sequence, characterized in that said means for estimating comprises: means for determining an estimated sequence (Y) based on the estimated channel impulse response and said copy of the transmitted training data sequence, and means for forming a sum of squared differences between corresponding elements of said estimated sequence and said received training data sequence, and determining a degree of match of said estimated sequence with said received training data sequence based on said sum.

Claim 19

A receiver as claimed in claim 16, characterized in that said corresponding elements are taken from the middle of said estimated and said received training data sequences.