Wireless communication apparatus and wireless communication system
A wireless communication apparatus includes a transmission circuit unit, a modulation unit, an encoding unit, a reception circuit unit, a phase adjustment unit, and an antenna unit, wherein the transmission circuit unit transmits a first modulated signal, as a first signal, which is encoded by the encoding unit based on a first clock signal and modulated by the modulation unit, to another wireless communication apparatus via a transmission path from the antenna unit, wherein the reception circuit unit generates a second clock signal based on a second signal received by the antenna unit from the other wireless communication apparatus, and wherein the phase adjustment unit detects a phase change caused by the transmission path based on the second clock signal, and controls a code of the first modulated signal based on the phase change.
1 . A wireless communication apparatus comprising:
a transmission circuit unit configured to transmit a first signal to another wireless communication apparatus via a first antenna unit;
an encoding unit configured to, based on a first clock signal, generate an encoded signal;
a modulation unit configured to, based on the encoded signal, generate a modulation signal that is the first signal
a reception circuit unit configured to, based on a second signal received from the other wireless communication apparatus via a second antenna unit, generate a second clock signal; and
a phase adjustment unit, the phase adjustment unit including a phase comparison unit and a bit compensation unit, the phase comparison unit being configured to output a phase difference signal based on a phase difference between the first clock signal and the second clock signal, the bit compensation unit being configured to determine a compensation bit to be added and an addition period of the compensation bit, based on the phase difference signal,
wherein the bit compensation unit inserts the compensation bit into the encoded signal at a bit boundary determined by the first clock signal to correct timing drift between the first clock signal and the second clock signal,
wherein after receipt of the second signal, the encoding unit outputs, to the modulation unit, a code to which the compensation bit is added, and
based on the code, the modulation unit performs modulation.
2 . The wireless communication apparatus according to claim 1 , wherein the compensation bit is 0 or 1.
3 . The wireless communication apparatus according to claim 1 , further comprising:
a switch configured to switch a unit to which the first clock signal is to be output to any one of the transmission circuit unit and the modulation unit, and the phase adjustment unit, and
a control unit configured to determine that a state where there is no output from the encoding unit is a stable state, and control the switch based on a determination result.
4 . The wireless communication apparatus according to claim 1 ,
wherein the other wireless communication apparatus includes
another reception circuit unit configured to, based on the first signal received via a third antenna unit, generate a third clock signal;
another encoding unit configured to, based on the third clock signal, generate an encoded signal;
another modulation unit configured to, based on the encoded signal, generate a modulation signal that is the second signal; and
another transmission circuit unit configured to transmit the second signal to the wireless communication apparatus via a fourth antenna unit.
5 . A wireless communication system comprising:
a first wireless communication apparatus; and
a second wireless communication apparatus,
wherein the first wireless communication apparatus includes:
a first transmission circuit unit configured to transmit a first signal to another wireless communication apparatus via a first antenna unit,
a first modulation unit configured to, based on the encoded signal, generate a modulation signal that is the first signal,
a first encoding unit configured to, based on a first clock signal, generate an encoded signal,
a first reception circuit unit configured to, based on a second signal received from the other wireless communication apparatus via a second antenna unit, generate a second clock signal, and
a phase adjustment unit, the phase adjustment unit including a phase comparison unit and a bit compensation unit, the phase comparison unit being configured to output a phase difference signal based on a phase difference between the first clock signal and the second clock signal, the bit compensation unit being configured to determine a compensation bit to be added and an addition period of the compensation bit, based on the phase difference signal,
wherein the bit compensation unit inserts the compensation bit into the encoded signal at a bit boundary determined by the first clock signal to correct timing drift between the first clock signal and the second clock signal,
wherein after receipt of the second signal, the encoding unit outputs, to the first modulation unit, a code to which the compensation bit is added, and based on the code, the first modulation unit performs modulation
wherein the second wireless communication apparatus includes:
a second transmission circuit unit configured to transmit the second signal to the wireless communication apparatus via a fourth antenna unit,
a second modulation unit configured to, based on the encoded signal, generate a modulation signal that is the second signal,
a second encoding unit configured to, based on the third clock signal, generate an encoded signal, and a second reception circuit unit configured to, based on the first signal received via a third antenna unit, generate a third clock signal.
6 . The wireless communication apparatus according to claim 1 , wherein the first signal transmitted via the first antenna and the second signal transmitted via the second antenna are different in frequency from each other.
7 . The wireless communication apparatus according to claim 1 , wherein in the encoded signal, 0 and 1 are at random and at substantially equal frequency.
8 . The wireless communication apparatus according to claim 1 , wherein the modulation unit generates the modulation signal using continuous phase frequency shift keying (CPFSK).