Patent ID: 7032161

Claim:
An error correcting and detecting device comprising: a viterbi decoder for correcting an error of a convolutional-coded bit string, and outputting a reception bit string in an order opposite to said convolutional-coded bit string; a receiving feedback shift register for dividing said reception bit string by a generator polynomial ad obtaining a value of said receiving feedback shift register after the dividing; and a comparing unit for comparing said value of the receiving feedback shift register with an initial code of a transmitting feedback shift register of a transmitter side, wherein said transmitting feedback shift register has stages setting logical values as the initial code, the logical values being the same as the transmitting feedback shift register's initial state, said comparing unit has a judging circuit that judges that there are no errors when logical values maintained at stages of the receiving feedback shift register after the receiving feedback shift register has shifted are all the same as the initial code, and said receiving feedback shift register has a shift direction and a feedback direction which are opposite to ones in generating a transmission bit stream by using a specified generator polynomial at said transmitter side, and said receiving feedback shift register and said comparing unit constitute an error detector for detecting an error of said reception bit string based on said logical value of the receiving feedback shift register.