An apparatus for producing a pseudo random - noise signal

摘要

Apparatus and a method are disclosed for synthesizing a pseudorandom communications signal having a smooth, flat, power spectrum. The system comprises frequency modulation circuitry for deriving a first analog signal from a digital encoding signal. The first analog signal is derived to have a substantially constant amplitude and a frequency varying in response to the amplitude of the digital encoding signal. Fourier transform circuitry is connected to the modulation circuitry and is operative to derive a second analog signal from the first analog signal. The resulting second analog signal is the fourier transform of the first analog signal, having a substantially constant power spectral density over the bandwidth of said second analog signal, and having an amplitude that varies in response to the amplitude of the digital encoding signal.