Space telemetry degradation due to Manchester data asymmetry induced carrier tracking phase error

The author analyzes the deleterious effects that the Manchester (or Bi-φ) data asymmetry has on the performance of phase-modulated residual carrier communication systems. Expressions for the power spectral density of an asymmetric Manchester data stream, the interference-to-carrier signal power ratio (I/C), and the error probability performance are derived. Since data asymmetry can cause undesired spectral components at the carrier frequency, the I/C ratio is given as a function of both the data asymmetry and the telemetry modulation index. Further, the data asymmetry and asymmetry-induced carrier tracking loop and the system bit-error rate to various parameters of the models are presented