Effects of HPA-Nonlinearity on a 4-DPSK/OFDM-Signal for a Digital Sound Broadcasting System.

摘要: Orthogonal Frequency Division Multiplexing (OFDM) in conjunction with a 4-DPSK modulation format has been proposed for the future digital audio broadcasting system (DAB), that should provide compact disk sound quality portable, vehicular and fixed receivers. With properly chosen parameters, this be appropriate both terrestrial satellite transmission. In paper influence of nonlinear distortions introduced by high power amplifier (HPA) transmitter is examined. particular, degradation efficiency due to intermodulation effects backoff operating, as well spectral degradations are investigated.It shown three different kinds limiting models, even an output (OBO) region 5-6 dB, of, e.g., 512-carrier 4-DPSK/OFDM relative linear case below 1.7 while regenerated sidelobes transmitted spectrum kept -20 dB.