OOK , ASK and FSK Modulation in the Presence of an Interfering signal

This paper discusses three popular modulation schemes in the presence of an interfering signal. For the purpose of our discussion OOK modulation (On/Off Key) is the special case of ASK (Amplitude Shift Key) modulation where no carrier is present during the transmission of a zero. FSK modulation (Frequency Shift Key) is commonly believed to perform better in the presence of interfering signals. However, it is usually more difficult and expensive to implement. This paper will review the three modulation types and develop a mathematical model for the prediction of error due to interference. This is then followed by laboratory test results.