• ADJACENT CHANNEL INTERFERENCE MEASUREMENTS WITH CPFSK AND FQPSK-B SIGNALS

      Law, Eugene; NAWCWD (International Foundation for Telemetering, 2001-10)
      This paper will present measured data in an adjacent channel interference (ACI) environment for both filtered continuous phase frequency shift keying (CPFSK) and Feher’s patented quadrature phase shift keying (FQPSK-B) [1]. The quantity measured was bit error probability (BEP) versus signal energy per bit to noise power spectral density ratio (E(b)/N(o)). The interferers were either CPFSK or FQPSK-B signals. The results presented in this paper will be for bit rates of 5 Mb/s, one interferer 20 dB larger than desired signal, various channel spacings, and two different telemetry receivers. The ACI test effort will collect data sets at several bit rates and with one and two interferers. The results will be useful to system designers and range operators as they attempt to maximize the number of Mb/s that can be simultaneously transmitted in the telemetry bands.