Patent ID: 8774042

Claim:
A transmitted rate detecting method of a communication apparatus, the communication apparatus used for receiving an input signal transmitted from a remote apparatus at a first rate or a second rate, the transmitted rate detecting method comprising: receiving the input signal with an initial receiving rate; sampling the input signal with a specific sample frequency to generate a sample result; determining an input transmitted rate of the input signal according to the sample result so as to set a receiving rate of the communication apparatus as a working rate; and communicating with the remote apparatus at the working rate; wherein the second rate is higher than the first rate, and the specific sample frequency is associated with the initial receiving rate; and the step of determining the input transmitted rate of the input signal according to the sample result so as to set the receiving rate of the communication apparatus as the working rate comprises: gathering statistics for an average of clock cycles of a first symbol's occurrence or a second symbol's occurrence in the sample result, wherein the first symbol is formed by a segment of at least N consecutive bits ‘ 0 ’, and the second symbol is formed by a segment of at least N consecutive bits ‘ 1 ’; deciding the input transmitted rate by determining whether the average of clock cycles falls within a predetermined range so as to generate a determination result; and setting the working rate as the first rate or the second rate according to the determination result.