An evaluation of the tone calibrated technique for data transmission over land mobile radio channels

The performance in land mobile radio channels of the Tone Calibrated Technique for data transmission originally proposed by the Jet Propulsion Laboratory is experimentally evaluated. A transmitter implementation allowing spectral shaping at baseband is presented. A phase coherent receiver structure is also presented which uses a hard limiter to remove the fading envelope. Data on the performance of this tone calibrated system and of a frequency shift keyed system are compared. A simple method of evaluating a modulation system for fading protection is advanced. By observing the response of the system to a double sideband modulated tone interferer a rough idea of the performance of the system in fading can be obtained.