Techniques for time domain automatic gain control for a frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) system

A method for a frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) system, comprising:

• detecting a return beam received from a target, the return beam comprising a first difference between a first highest intensity and a first lowest intensity;
• generating a digital signal based on the return beam detected;
• and
• applying variable gain to the digital signal in a time domain to reduce the first difference to a second difference comprising a second highest intensity and a second lowest intensity beam to increase a signal strength of the digital signal for processing by a processor resident on the FMCW LIDAR system.

A frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) system, comprising:

• a light source to generate a light signal;
• an optical circuit comprising
• a modulator to modulate the light signal to generate a pulsed light signal transmitted towards a target;
• and
• a photodetector to detect a return beam from the target based on the pulsed light signal, the return beam comprising a first difference between a first highest intensity and a first lowest intensity;
• an analog to digital converter (ADC) to generate a digital signal based on the return beam detected at the photodetector;
• and
• an automatic gain control (AGC) unit to:
• apply a variable gain to the digital signal in a time domain to reduce the first difference to a second difference comprising a second highest intensity and a second lowest intensity to increase a signal strength of the digital signal for processing;
• a processing device coupled to the photodetector configured to:
• perform time domain processing on the digital signal in the time domain;
• convert the digital signal from the time domain to a frequency domain;
• and
• perform frequency domain processing on the digital signal in the frequency domain.