Study on construction of wireless 2-hop transmission simulator by H8 microcomputer board

Various techniques have been studied in order to realize high-speed wireless network. Many wireless transmission technologies are usually validated by theoretical analysis or computer simulations assuming ideal conditions. However, actual wireless transmission performance may be degraded by the error caused by hardware limitation. Therefore, it is necessary to validate these techniques by hardware simulations for practical use. Furthermore, the visualization of the waveform by an oscilloscope or a spectrum analyzer is helpful for promotion of research. Cognitive radio system which can change the modulation scheme, i.e. adaptively by rewriting the software, has attracted attention. There is a great demand for general purpose software defined wireless transmitter and receiver. Such wireless transmitter and receiver can be realized using signal generator and vector signal analyzer which are commercial products. However, these equipments are most of the time expensive. There exist also inexpensive devices like H8 microcomputer board. This can be programmed using C language. However, because of the limitation of H8 microcomputer board hardware performance, high-end functions are not available and the size of variable is limited. In this paper, we build a 2-hop wireless transmission simulator by using a single H8 board microcomputer. The signals are visualized by an oscilloscope. The bit error rate performance is evaluated and the results well agree with the theoretical values.