Minimum Shift Keying (MSK), uses two frequencies which are separated by 1/2T and phase discontinuity is avoided in symbol boundaries. Further, MSK transmission can also be visualized as a variant of offset-QPSK technique, where sinusoidals are used for pulse shaping instead of rectangular.

Further, we will discuss the receiver structure and show that bit error rate with coherent demodulation of MSK is equivalent to that of BPSK modulation. The channel assumed is AWGN.

Further details on the MSK transmitter and receiver is discussed in the post
http://www.dsplog.com/2009/06/16/msk-transmitter-receiver/

The simulation results for varying values of Eb/N0 is provided in the attached script.