Two-state automatic gain control for communications and radar

1. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to:

transmit a radar signal via a first antenna array, while receiving a reflected radar signal via a second antenna array;

receive a first data signal or a pilot signal via the second antenna array;

use a first automatic gain control unit to receive the first data signal, wherein the second antenna array is connected to the first automatic gain control unit, while receiving the first data signal or the pilot signal;

use a second automatic gain control unit to receive the reflected radar signal, wherein the second antenna array is connected to the second automatic gain control unit, while receiving the reflected radar signal;

switch between using the first automatic gain control unit and using the second automatic gain control unit.

2. The apparatus according to claim 1 , wherein the apparatus is further caused to:

transmit a second data signal via the first antenna array;

receive a third data signal via the first antenna array.

3. The apparatus according to claim 1 , wherein the received first data signal and the received reflected radar signal use a substantially same carrier frequency.

4. The apparatus according to claim 1 , wherein the apparatus is further caused to perform a first time averaging for the received first data signal and a second time averaging for the received reflected radar signal.

5. The apparatus according to claim 1 , wherein the apparatus is further caused to:

determine a first beat frequency based at least partly on a first carrier frequency of the received reflected radar signal;

determine a second beat frequency based at least partly on a second carrier frequency of the received reflected radar signal;

determine a velocity of a target based at least partly on the first beat frequency and the second beat frequency.

6. The apparatus according to claim 1 , wherein the apparatus is further caused to:

receive automatic gain control state information, wherein the automatic gain control state information indicates whether a received signal is the reflected radar signal or not, or a state change for switching between using the first automatic gain control unit and using the second automatic gain control unit.

7. The apparatus according to claim 6 , wherein the automatic gain control state information is configured to adapt a power amplifier operation point or to indicate whether to enable or disable a gain adjustment in the first automatic gain control unit or in the second automatic gain control unit.

8. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to:

transmit a radar signal via a first antenna array, while receiving a reflected radar signal via the first antenna array, wherein the first antenna array comprises a first subarray and a second subarray, wherein the first subarray is used to transmit the radar signal, and wherein the second subarray is used to receive the reflected radar signal;

receive a first data signal via the first antenna array, wherein the first subarray and the second subarray are used to receive the first data signal;

use a first automatic gain control unit to receive the first data signal, wherein the first antenna array is connected to the first automatic gain control unit, while receiving the first data signal;

use a second automatic gain control unit to receive the reflected radar signal, wherein the first antenna array is connected to the second automatic gain control unit, while receiving the reflected radar signal;

switch between using the first automatic gain control unit and using the second automatic gain control unit.

9. The apparatus according to claim 8 , wherein the apparatus is further caused to:

transmit a second data signal via the first antenna array, wherein the first subarray and the second subarray are used to transmit the second data signal.

10. The apparatus according to claim 8 , wherein the apparatus is further caused to:

receive antenna array partitioning state information, wherein the antenna array partitioning state information indicates at least whether the first subarray is used for transmitting or receiving, and whether the second subarray is used for transmitting or receiving.

11. The apparatus according to claim 8 , wherein the received first data signal and the received reflected radar signal use a substantially same carrier frequency.

12. The apparatus according to claim 8 , wherein the apparatus is further caused to perform a first time averaging for the received first data signal and a second time averaging for the received reflected radar signal.

13. The apparatus according to claim 8 , wherein the apparatus is further caused to:

determine a first beat frequency based at least partly on a first carrier frequency of the received reflected radar signal;

determine a second beat frequency based at least partly on a second carrier frequency of the received reflected radar signal;

determine a velocity of a target based at least partly on the first beat frequency and the second beat frequency.

14. The apparatus according to claim 8 , wherein the apparatus is further caused to:

receive automatic gain control state information, wherein the automatic gain control state information indicates whether a received signal is the reflected radar signal or not, or a state change for switching between using the first automatic gain control unit and using the second automatic gain control unit.

15. The apparatus according to claim 14 , wherein the automatic gain control state information is configured to adapt a power amplifier operation point or to indicate whether to enable or disable a gain adjustment in the first automatic gain control unit or in the second automatic gain control unit.

16. A method, comprising:

transmitting a radar signal via a first antenna array, while receiving a reflected radar signal via a second antenna array;

receiving a first data signal or a pilot signal via the second antenna array;

using a first automatic gain control unit to receive the first data signal, wherein the second antenna array is connected to the first automatic gain control unit, while receiving the first data signal or the pilot signal;

using a second automatic gain control unit to receive the reflected radar signal, wherein the second antenna array is connected to the second automatic gain control unit, while receiving the reflected radar signal;

switching between using the first automatic gain control unit and using the second automatic gain control unit.

17. The method according to claim 16 , further comprising:

transmitting a second data signal via the first antenna array;

receiving a third data signal via the first antenna array.

18. The method according to claim 16 , wherein the received first data signal and the received reflected radar signal use a substantially same carrier frequency.

19. The method according to claim 16 , further comprising:

performing a first time averaging for the received first data signal and a second time averaging for the received reflected radar signal.

20. The method according to claim 16 , further comprising:

determining a first beat frequency based at least partly on a first carrier frequency of the received reflected radar signal;

determining a second beat frequency based at least partly on a second carrier frequency of the received reflected radar signal; and

determining a velocity of a target based at least partly on the first beat frequency and the second beat frequency.