Realization of low-cost spectrum shaping filter for digital radio-relay systems with direct modulation

摘要

In this paper we described the realization of low cost spectrum shaping filter for digital radio-relay systems with direct modulation, which is made as a cascade connection of digital FIR and analogue Butterworth filter. FIR filter operates at twice the symbol rate, and its coefficients are chosen for minimising FPGA or CPLD chip resources needed for realisation.