Communication apparatus and method

1 . A communication apparatus of an electronic toll collection (ETC) system, comprising:

at least one transmit antenna;

at least one receive antenna;

and a signal processor separately connected to the at least one transmit antenna and the at least one receive antenna, and configured to:

control the at least one transmit antenna and the at least one receive antenna to communicate with at least one first terminal on a first frequency band that comprises a first subband and a second subband, wherein the first subband and the second subband do not overlap;

send a first communication signal to the at least one first terminal on the first subband through the at least one transmit antenna; and

control at least one target transmit antenna to send a radar signal on a second frequency band, and control at least one target receive antenna to receive a first echo signal of the radar signal on the second frequency band, wherein the first echo signal comprises an echo signal corresponding to at least one target, the at least one transmit antenna comprises the at least one target transmit antenna, the at least one receive antenna comprises the at least one target receive antenna, the first frequency band and the second frequency band do not overlap, and a bandwidth of the radar signal is greater than a bandwidth of the first communication signal;

wherein the communication apparatus performs tracking, positioning, and speed measurement on the at least one first terminal based on the first echo signal.

2 . The communication apparatus according to claim 1 , wherein one or more of the at least one transmit antenna comprise at least one right-handed circular polarization antenna.

3 . The communication apparatus according to claim 1 , wherein one or more of the at least one target receive antenna comprise at least one linear polarization antenna.

4 . The communication apparatus according to claim 3 , wherein the at least one linear polarization antenna comprises at least one horizontal polarization antenna or at least one vertical polarization antenna.

5 . The communication apparatus according to claim 1 , wherein one or more of the at least one target receive antenna comprise at least one linear polarization antenna combination that comprises a pair of linear polarization antennas that are orthogonally polarized.

6 . The communication apparatus according to claim 5 , wherein the at least one linear polarization antenna combination comprises a horizontal polarization antenna and a vertical polarization antenna.

7 . The communication apparatus according to claim 1 , wherein the signal processor is further configured to:

receive a second communication signal from the at least one first terminal on the second subband through the at least one receive antenna, wherein the bandwidth of the radar signal is greater than a bandwidth of the second communication signal.

8 . The communication apparatus according to claim 7 , further comprising:

at least one receive radio frequency unit; and

at least one receive feed unit;

wherein the at least one target receive antenna, the at least one receive feed unit, and the at least one receive radio frequency unit correspond to each other, the at least one target receive antenna is connected to an input end of the at least one receive feed unit, an output end of the at least one receive feed unit is connected to an input end of the at least one receive radio frequency unit, and an output end of the at least one receive radio frequency unit is connected to the signal processor.

9 . The communication apparatus according to claim 8 , wherein

each of the at least one target receive antenna comprises at least one linear polarization antenna combination that comprises a horizontal polarization antenna and a vertical polarization antenna;

the at least one receive feed unit is configured to:

receive a horizontal polarization signal from a horizontal polarization antenna in the target receive antenna corresponding to the receive feed unit and a vertical polarization signal from a vertical polarization antenna in the target receive antenna corresponding to the receive feed unit;

move a phase of the vertical polarization signal forward by 90 degrees relative to a phase of the horizontal polarization signal to obtain the first echo signal;

move the phase of the horizontal polarization signal forward by 90 degrees relative to the phase of the vertical polarization signal to obtain the second communication signal;

perform combination processing on the first echo signal and the second communication signal to obtain a combined signal; and

send the combined signal to the receive radio frequency unit corresponding to the receive feed unit;

the receive radio frequency unit corresponding to the receive feed unit is configured to receive the combined signal, and send the combined signal to the signal processor; and

the signal processor is further configured to:

receive the combined signal;

obtain the second communication signal from the combined signal based on the second subband; and

obtain the first echo signal from the combined signal based on the second frequency band.

10 . The communication apparatus according to claim 7 , further comprising:

at least one receive radio frequency unit group; and

at least one receive feed unit;

wherein the at least one target receive antenna, the at least one receive feed unit, and the at least one receive radio frequency unit group correspond to each other, the at least one target receive antenna is connected to an input end of the at least one receive feed unit, an output end of the at least one receive feed unit is connected to an input end of the at least one receive radio frequency unit group, an output end of the at least one receive radio frequency unit group is connected to the signal processor, and the receive radio frequency unit group comprises a first receive radio frequency unit and a second receive radio frequency unit.

11 . The communication apparatus according to claim 10 , wherein

each of the at least one target receive antenna comprises at least one linear polarization antenna combination that comprises a horizontal polarization antenna and a vertical polarization antenna;

the at least one receive feed unit is configured to:

receive a horizontal polarization signal from the horizontal polarization antenna and a vertical polarization signal from the vertical polarization antenna;

move a phase of the vertical polarization signal forward by 90 degrees relative to a phase of the horizontal polarization signal to obtain the first echo signal;

move the phase of the horizontal polarization signal forward by 90 degrees relative to the phase of the vertical polarization signal to obtain the second communication signal;

send the first echo signal to the first receive radio frequency unit in the receive radio frequency unit group corresponding to the receive feed unit; and

send the second communication signal to the second receive radio frequency unit in the receive radio frequency unit group corresponding to the receive feed unit;

the first receive radio frequency unit in the receive radio frequency unit group corresponding to the receive feed unit is configured to receive the first echo signal from the receive feed unit, and send the first echo signal to the signal processor; and

the second receive radio frequency unit in the receive radio frequency unit group corresponding to the receive feed unit is configured to receive the second communication signal from the receive feed unit, and send the second communication signal to the signal processor.

12 . The communication apparatus according to claim 7 , wherein a guard band is comprised between at least two of: the first subband, the second subband, and the second frequency band.

13 . The communication apparatus according to claim 1 , wherein

a quantity of the at least one transmit antenna is greater than 1, and a quantity of the at least one target transmit antenna is less than the quantity of the at least one transmit antenna; or

a quantity of the at least one receive antenna is greater than 1, and a quantity of the at least one target receive antenna is less than the quantity of the at least one receive antenna.

14 . The communication apparatus according to claim 1 , wherein the at least one target comprises at least one second terminal that comprises the at least one first terminal.

15 . A communication method for an electronic toll collection (ETC) system, the method comprising:

controlling at least one transmit antenna and at least one receive antenna to communicate with at least one first terminal on a first frequency band that comprises a first subband and a second subband, wherein the first subband and the second subband do not overlap;

sending a first communication signal to the at least one first terminal on the first subband through the at least one transmit antenna;

controlling at least one target transmit antenna to send a radar signal on a second frequency band, and controlling at least one target receive antenna to receive a first echo signal of the radar signal on the second frequency band, wherein the first echo signal comprises an echo signal corresponding to at least one target, the at least one transmit antenna comprises the at least one target transmit antenna, the at least one receive antenna comprises the at least one target receive antenna, the first frequency band and the second frequency band do not overlap, and a bandwidth of the radar signal is greater than a bandwidth of the first communication signal; and

performing tracking, positioning, and speed measurement on the at least one first terminal based on the first echo signal.

16 . The communication method according to claim 15 , wherein one or more of the at least one transmit antenna comprise at least one right-handed circular polarization antenna.

17 . The communication method according to claim 15 , wherein one or more of the at least one target receive antenna comprise at least one linear polarization antenna.

18 . The communication method according to claim 17 , wherein the at least one linear polarization antenna comprises at least one horizontal polarization antenna or at least one vertical polarization antenna.

19 . The communication method according to claim 15 , wherein one or more of the at least one target receive antenna comprise at least one linear polarization antenna combination that comprises a pair of linear polarization antennas that are orthogonally polarized.

20 . The communication method according to claim 19 , wherein the linear polarization antenna combination comprises a horizontal polarization antenna and a vertical polarization antenna.