| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmission device capable of transmitting at a stable frequency.SOLUTION: In a transmission device having a transmission controller for transmitting different modulation data signals from plural antennas at the same frequency of 1200 MHz by an OFDM system, a single cable and a transmission high frequency unit, the transmission controller frequency-converts OFDM modulation waves to positive phase and inverted phase of the frequency 3CLO which are three times as high as the frequency (10 MHz) of a common local oscillator CLO corresponding to 30 MHz of the difference of 130 MHz and 190 MHz, the signal which is frequency-converted to the positive phase and inverted phase of 30 MHz is frequency-converted by 16 CLO which is equal to 160 MHz as the average of IF2 and IF1, 130 MHz and 190 MHz are taken out, 130 MHz and 190 MHz are transmitted by using a single coaxial cable, and the transmission high frequency unit converts transmitted 130 MHz and 190 MHz to 160 MHz by 3CLO, converts 160 MHz to 1200 MHz by 104CLO, and transmits from an antenna.SELECTED DRAWING: Figure 10 |
