Application and analysis of rake receiver to hybrid CPM modulation

Constant Envelope, Spread Spectrum Modulation is highly desirable for low-power, battery-operated systems. It has been demonstrated that Hybrid CPM is a constant envelope modulation with similar frequency diversity properties to the standard spread-spectrum m-PSK DSSS and spread-MSK modulation schemes while retaining a superior emissions profile. This paper continues the analysis of the novel constant envelope spread spectrum modulation technique with an analysis of the commonly utilized rake receiver signal processing. Initially, a simple channel model is developed to illustrate and compare the convergence of the channel estimate over a fixed, non-time-varying channel. A more complex, wireless channel model is then developed and a new corresponding method for channel estimation created. A Monte- Carlo simulated bit error rate performance of Hybrid CPM is then generated to evaluate the overall performance of the Hybrid CPM modulation scheme.