Control of optical receiver based on environmental condition

1. An apparatus, the apparatus being part of a Light Detection and Ranging (LiDAR) module of a vehicle and comprising:

a receiver circuit including a photodiode and an amplifier circuit; and

a controller configured to:

obtain an ambient light intensity;

based on the ambient light intensity, set a multiplication ratio by which the photodiode converts incident light to a photocurrent;

obtain, from the amplifier circuit, an output signal based on the photocurrent; and

perform a ranging operation based on the output signal;

wherein the controller is further configured to set the multiplication ratio to a first ratio based on the ambient light intensity within a first intensity range, and set the multiplication ratio to a second ratio based on the ambient light intensity within a second intensity range.

2. The apparatus of claim 1 , wherein the controller is further configured to:

control a light source of the LiDAR module to transmit a first light signal;

detect, from the output signal of the amplifier circuit, a second light signal reflected by an object from the first light signal;

measure a time difference between when the first light signal is transmitted by the light source and when the second light signal is received by the receiver circuit; and

determine a distance between the apparatus and the object based on the time difference.

3. The apparatus of claim 1 , wherein the controller is further configured to:

control a light source of the LiDAR module to transmit multiple first light signals;

detect, from the output signal of the amplifier circuit, multiple second light signals reflected by an object from the multiple first light signals;

measure multiple time differences between when the multiple first light signals are transmitted by the light source and when the multiple second light signals are received by the receiver circuit; and

determine a distance between the apparatus and the object based on the multiple time differences.

4. The apparatus of claim 1 ,

wherein the first intensity range is lower than the second intensity range; and

wherein the first ratio is larger than the second ratio.

5. The apparatus of claim 1 , wherein the controller has access to a mapping table that maps ambient light intensities to different multiplication ratios; and

wherein the controller is configured to retrieve the multiplication ratio from the mapping table based on the ambient light intensity.

6. The apparatus of claim 5 , wherein each multiplication ratio in the mapping table is determined to achieve at least one of: a target signal-to-noise ratio (SNR) for ambient light intensity, or a maximum SNR for the ambient light intensity.

7. The apparatus of claim 1 , wherein the controller has access to a mapping table that maps different operation conditions to different settings of the photodiode, each setting corresponding to a multiplication ratio; and

wherein the controller is configured to:

retrieve a setting from the mapping table based on the ambient light intensity; and

configure the receiver circuit based on the setting to set the multiplication ratio.

8. The apparatus of claim 7 , wherein the setting comprises at least one of:

a reverse-biased voltage across the photodiode, or a bias current of the photodiode.

9. The apparatus of claim 1 , wherein the controller is configured to obtain the ambient light intensity from one or more sensors.

10. The apparatus of claim 1 , wherein the photodiode comprises at least one of:

an avalanche photodiode (APD), a P-I-N diode, a single photodiode avalanche photodiode (SPAD), or a silicon photomultiplier (SiPM).

11. A method comprising:

obtaining, in a Light Detection and Ranging (LiDAR) module, an ambient light intensity;

based on the ambient light intensity, setting a multiplication ratio by which a photodiode of a receiver circuit of the LiDAR module converts incident light to a photocurrent;

obtaining, from an amplifier circuit of the receiver circuit, an output signal generated from the photocurrent; and

performing a ranging operation based on the output signal;

wherein setting the multiplication ratio comprises:

setting the multiplication ratio to a first ratio based on the ambient light intensity within a first intensity range; and

setting the multiplication ratio to a second ratio based on the ambient light intensity within a second intensity range.

12. The method of claim 11 , further comprising:

controlling a light source of the LiDAR module to transmit a first light signal;

detecting, from the output signal of the amplifier circuit, a second light signal reflected by an object from the first light signal; and

determining a distance between the LiDAR module and the object based on the first light signal and the second light signal.

13. The method of claim 11 ,

wherein the first intensity range is lower than the second intensity range; and

wherein the first ratio is larger than the second ratio.