Patent ID: 6167079
Filing Date: 2000-12-26
Classification: H04L

Abstract:
A method for identifying data transmission rate from a signal composed of a succession of frames, which signal has several transmission rate alternatives and comprises modulation symbols (201 to 206) which are formed as a vector and which are submatrices of a known modulation matrix selected on the basis of a combination of bits to be transmitted, in which method a correlation is formed between a received modulation symbol (201 to 206) and the known modulation matrix, as a result of which at least one correlation vector (301 to 306) is produced, the at least one correlation vector comprising correlation values (311) and by means of which the signal is detected, characterized in that by utilizing the correlation values (311) of the at least one correlation vector (301 to 306), an estimate (556) is formed for each data transmission rate representing the probability of the data transmission rate of the signal, andthat by means of the estimates (556), the most probable data transmission rate is selected to be used for detecting the signal,and further characterized in that when each frame comprises time slots (101 to 116), the estimate (556) representing the probability of the transmission rate is formed in such a manner thata quality value (552 and 554) based on the correlation values of at least one time slot (101 to 116) is formed,by comparing the quality value (552 and 554) of the at least one time slot (101 to 116) to one another by data transmission rates, the estimate representing the probability of the data transmission rate is formed.