Modem Design using Continuous Phase Modulation with Coding

The combination of coding and low index modulation can result in both bandwidth and power efficient modem design. The low index modulation format is obtained by using a frequency division and multiplication network to alter the modulation index of ¿ for convertioned MSK to a lower value. This lower value modulation index in concert with restricted range encoding provides a system that can achieve a 2 bits/sec/Hz bandwidth efficiency at a power level equivalent to that required for MSK. The design concepts are such that data rates in the hundreds of megabits/second are practical.