Noncoherent modulation is an important technique in wireless communication systems. Although noncoherent modulation usually does not perform as well as its coherent counterpart it is practical and useful in some applications, such as paging systems. In this thesis we investigate ways to improve the performance of noncoherent FSK in narrowband channels. It is shown that FSK permutation modulation has better spectral efficiency than conventional FSK modulation" but with the tradeoff on reduced energy efficiency. To overcome this problem, we apply trellis-coded modulation (TCM) , which is a combined technology of convolutional coding and modulation, to FSK permutation. TCM was originally designed for coherent modulation. The application of TCM to permutation modulation retains the fundamental concepts of TCM. The simulation results show that trellis-coded permutation modulation provides a better combination of energy efficiency and spectral efficiency than conventional FSK noncoherent demodulation. / Master of Science