Transmitter hardware sharing

1 . A transmitter circuit for wireless communications, comprising:

a first transmit chain configured to support a first radio access technology (RAT); and

a second transmit chain configured to support a second RAT different from the first RAT, wherein the first transmit chain and the second transmit chain share a digital-to-analog converter (DAC) and wherein the DAC is configured to output a first signal associated with the first RAT at a first time and a second signal associated with the second RAT at a second time different than the first time.

2 . The transmitter circuit of claim 1 , wherein the first transmit chain and the second transmit chain share the DAC and a frequency synthesizer.

3 . The transmitter circuit of claim 2 , wherein:

the first transmit chain comprises a first baseband filter and a first mixer, the first mixer having a first input coupled to an output of the first baseband filter;

the second transmit chain comprises a second baseband filter and a second mixer, the second mixer having a first input coupled to an output of the second baseband filter;

a first output of the DAC is coupled to an input of the first baseband filter;

a second output of the DAC is coupled to an input of the second baseband filter; and

an output of the frequency synthesizer is coupled to a second input of the first mixer and to a second input of the second mixer.

4 . The transmitter circuit of claim 3 , wherein:

the first transmit chain further comprises a first baseband processor having an output coupled to an input of the DAC; and

the second transmit chain further comprises a second baseband processor having an output coupled to the input of the DAC.

5 . The transmitter circuit of claim 2 , wherein the first transmit chain and the second transmit chain share the DAC, the frequency synthesizer, and a baseband processor having an output coupled to an input of the DAC.

6 . The transmitter circuit of claim 1 , wherein the first transmit chain and the second transmit chain share the DAC and a baseband processor having an output coupled to an input of the DAC.

7 . The transmitter circuit of claim 1 , wherein a third signal is configured to be output from the first transmit chain at a third time, wherein a fourth signal is configured to be output from the second transmit chain at a fourth time, and wherein the fourth time is different than the third time.

8 . The transmitter circuit of claim 1 , wherein the first transmit chain comprises a cellular vehicle-to-everything (C-V2X) transmit chain and wherein the second transmit chain comprises a FR2 or millimeter wave transmit chain.

9 . The transmitter circuit of claim 1 , wherein the first transmit chain comprises a FR1 or sub-6 GHz transmit chain and wherein the second transmit chain comprises a FR2 or millimeter wave transmit chain.

10 . The transmitter circuit of claim 1 , further comprising:

a third transmit chain; and

a fourth transmit chain, wherein the third transmit chain and the fourth transmit chain are configured to share at least one of another DAC or a frequency synthesizer.

11 . The transmitter circuit of claim 10 , wherein:

the first transmit chain comprises a cellular vehicle-to-everything (C-V2X) transmit chain;

the second transmit chain comprises a first FR2 or millimeter wave transmit chain;

the third transmit chain comprises a FR1 or sub-6 GHz transmit chain; and

the fourth transmit chain comprises a second FR2 or millimeter wave transmit chain.

12 . The transmitter circuit of claim 1 , further comprising one or more additional transmit chains, wherein a total number of transmit chains in the transmitter circuit is greater than a number of transmit chains from which signals can be concurrently transmitted.

13 . The transmitter circuit of claim 1 , further comprising at least one additional transmit chain, wherein the first transmit chain, the second transmit chain, and the at least one additional transmit chain share the DAC.

14 . A method of wireless communication, comprising:

converting a first digital signal to a first analog signal associated with a first radio access technology (RAT) at a first time using a digital-to-analog converter (DAC);

processing the first analog signal using a first transmit chain that supports the first RAT to generate a first radio frequency (RF) signal for transmission;

converting a second digital signal to a second analog signal associated with a second RAT at a second time using the DAC, the second RAT being different from the first RAT and the second time being different than the first time; and

processing the second analog signal using a second transmit chain that supports the second RAT to generate a second RF signal for transmission, wherein the first transmit chain and the second transmit chain share the DAC.

15 . The method of claim 14 , wherein the first transmit chain and the second transmit chain share the DAC and a frequency synthesizer.

16 . The method of claim 15 , wherein:

the first transmit chain comprises a first baseband filter and a first mixer;

processing the first analog signal comprises:

filtering the first analog signal with the first baseband filter to generate a first filtered analog signal; and

mixing, with the first mixer, the first filtered analog signal with a first oscillating signal derived from the frequency synthesizer to generate a first preliminary RF signal, the first RF signal being based on the first preliminary RF signal;

the second transmit chain comprises a second baseband filter and a second mixer; and

processing the second analog signal comprises:

filtering the second analog signal with the second baseband filter to generate a second filtered analog signal; and

mixing, with the second mixer, the second filtered analog signal with a second oscillating signal derived from the frequency synthesizer to generate a second preliminary RF signal, the second RF signal being based on the second preliminary RF signal.

17 . The method of claim 15 , wherein:

the first transmit chain and the second transmit chain share the DAC, the frequency synthesizer, and a baseband processor; and

the method further comprises:

outputting the first digital signal from the baseband processor; and

outputting the second digital signal from the baseband processor.

18 . The method of claim 14 , wherein:

the first transmit chain and the second transmit chain share the DAC and a baseband processor; and

the method further comprises:

outputting the first digital signal from the baseband processor; and

outputting the second digital signal from the baseband processor.

19 . The method of claim 14 , further comprising:

transmitting the first RF signal at a third time; and

transmitting the second RF signal at a fourth time, wherein the fourth time is different than the third time.

20 . The method of claim 14 , wherein the first transmit chain comprises a cellular vehicle-to-everything (C-V2X) transmit chain and wherein the second transmit chain comprises a FR2 or millimeter wave transmit chain.

21 . The method of claim 14 , wherein the first transmit chain comprises a FR1 or sub-6 GHz transmit chain and wherein the second transmit chain comprises a FR2 or millimeter wave transmit chain.

22 . The method of claim 14 , further comprising:

converting a third digital signal to a third analog signal using another DAC;

processing the third analog signal using a third transmit chain to generate a third RF signal for transmission;

converting a fourth digital signal to a fourth analog signal using the other DAC; and

processing the fourth analog signal using a fourth transmit chain to generate a fourth RF signal for transmission, wherein the third transmit chain and the fourth transmit chain share the other DAC.

23 . The method of claim 22 , wherein the third transmit chain and the fourth transmit chain share the other DAC and a frequency synthesizer.

24 . The method of claim 22 , wherein:

the first transmit chain comprises a cellular vehicle-to-everything (C-V2X) transmit chain;

the second transmit chain comprises a first FR2 or millimeter wave transmit chain;

the third transmit chain comprises a FR1 or sub-6 GHz transmit chain; and

the fourth transmit chain comprises a second FR2 or millimeter wave transmit chain.

25 . The method of claim 14 , further comprising:

converting a third digital signal to a third analog signal using the DAC; and

processing the third analog signal using a third transmit chain to generate a third RF signal for transmission, wherein the first transmit chain, the second transmit chain, and the third transmit chain share the DAC.