When a CDMA signal is passed through an RF transmitter, nonlinear elements cause spectral regrowth which result in reduction of spectral efficiency. CDMA signal has a pseudo noise nature; hence its mathematical treatment is too complex to analysis. In this paper, first it will be shown how to simplify the complex mathematics of CDMA signal. Then a deterministic signal replaces the CDMA signal and then the system response to both of them is calculated. In this paper, for the first time, ACPR is explicitly calculated for both the CDMA and deterministic signals. ACPR is calculated in terms of the nonlinear system coefficients and input power, and therefore, can be used in design objectives. In addition, It will be shown that if input power of the deterministic signal is multiplied by (i.e. correction factor), ACPR error of these kinds of signals in -55dBc is less than 2.2% for the system nonlinearity orders up to 13. This correction factor is obtained by both theoretical and simulation methods.

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