Patent ID: 6137824
Filing Date: 2000-10-24
Classification: H04B

Abstract:
A method for estimating signal quality, the method being used in a spread spectrum radio system having several transmitters and receivers, and in which each transmitted signal is pseudonoise-coded by a separate spreading code into a wideband form and the signal being converted into modulation symbols having a vector form, said modulation symbols being submatrices of a substantially orthogonal known transform matrix, said submatrices being chosen on the basis of a combination of bits to be transmitted, the signal being multiplied by a spreading code in the receiver in which a correlation is formed between the received modulation symbols and the known transform matrix, the correlation forming correlation vectors which comprise correlation values and by means of which the signal is detected, wherein, when multiplying the received signal by a specific spreading code, an estimate representing the signal quality is formed by comparing the mean value of one or more correlation values of the correlation vector to the highest value of the correlation vector, in which the mean value of one or more correlation values comprises all other correlation values but the highest correlation value.