Theory of Multi-Frequency Modulation (MFM) Digital Communications
Abstract
Multi-frequency modulation (MFM) is a new digital signal processing (DSP) oriented communications signal developed at NPS specifically for computer- to-computer communications links and information exchange networks. MFM utilizes the hardware and software of the host computers to generate and to demodulate coherent communications discrete time signals. In this report, the theory behind MFM generation and reception is presented. Auto-correlation functions and power spectral densities of MFM signals are derived and examples presented for lowpass and bandpass white MFM sequences. The bit error rates are computed for three types of MFM: MFBPSK, MFQPSK and MF16-QAM. These modulation formats provide one, two and four bits per Hz of channel bandwidth respectively. Optimization arguments show that best system performance is obtained by using the maximum possible number of tones with the limit on the number of tones being set either by the packet length or the coherence time of the channel, whichever is shorter.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 05, 1989
- Accession Number
- ADA209737
Entities
People
- Paul H. Moose
Organizations
- Naval Postgraduate School