This paper describes a low-cost transmitting and receiving system for wireless communication. In a first part, the design and realization of a transmitter for modulated data at 2.45 GHz carrier frequency and with frequency, amplitude and phase modulation is handled. A second part explains the design and realization of a receiving module, which filters and downconverts the signals to an intermediate frequency. The postprocessing section describes the use of a DVB-T module together with open-source software, SDR#, for the final downconversion, as well as for the demodulation and the detection of the received signals in order to reproduce the originally transmitted data. Combining all components results in a low-cost and flexible software defined radio system.