| 摘要 |
<p>PURPOSE:To improve the stability and the reliability by exchanging information between a monitor device like a receiver or a repeater and a detector like a fire sensor installed in the field by radio transmission using the spectrum spread communication. CONSTITUTION:A repeater 3 is provided with a reception antenna 11, an SS reception part (spectrum spread reception part) 12, a PN sequence generator 13, and a control part 14 using a CPU. The SS reception part 12 uses the pseudo-random sequence signal generated by the PN sequence generator 13 to demodulate the reception signal received by the reception antenna 11. When a fire detection signal subjected to spectrum spread modulation is received from one of fire sensors 4a to 4n, data bits are outputted as a self-correlation peak value at the time of coincidence between the pseudo-random sequence included in the reception signal, and a reference pseudo-random sequence generated by the PN sequence generator 13, and the control part 14 restores original fire detection information based on data bits outputted from the reception part 12.</p> |
