Other Parts Discussed in Thread: ADC3221, ADC3421
Our Radar have to use 24GHz band, and TI's Radar chip all moved to 60/77 GHz band. So, we have to design our own radar, with functionality and processing power similar to AWR2944.
We have the 24GHz RF part, sweep frequency is controlled by VCO, and outputs analog IF signal. For the signal processing part, I am thinking using an external high-speed ADC and a DSP chip to mimic AWR2944.
For the ADC chip, our current Radar front end has 2 Rx channels, and ADC3221's 25Msps sampling rate seems a good fit. And it has serial LVDS interface.
In future, our Radar front end may scale up to 4 Rx (ADC3421) and 8 Rx (Two ADC3421).
However, the DSP chip is hard to choose. Following are some considerations:
- Have serial LVDS interface to receive ADC data from ADC3221.
- Need compute two sets of 1024-points real FFT (results in 512-points complex spectrum) in less than 30 us.
For single DSP core that perform two sets of FFT sequentially, each set shall be done in 15 us. This seems to require a C66x DSP core. - Have multi-core architecture. While the DSP core computes FFT, another core can do object tracking using Kalman filter or particle filter.
Does TI already have object tracking libraries? Is it on DSP core or ARM core? If not, is there any recommended 3rd-party/open-source libraries? - If the DSP chip does not support external RAM, its internal RAM must be more than 512k.
- Better to have DAC to generate sawtooth waveform.
For FMCW radar chirp generation with chirp duration of 30 us, would a high-speed (>10Msps) DAC be required?
If the DSP has no DAC, what external DAC to use? Do they also use serial LVDS interface like ADC3221? In that case, the DSP chip shall have multiple LVDS interface.
Or is there any better way than DAC to generate high-linearity, slope-configurable sawtooth ramps? - Better to have a smooth upgrade path for future 4/8 Rx channel upgrades.
- Chips shall have sufficient inventory, normal lead-time, and unlikely to suffer shortage issue.
- Cost less than $30.
I couldn't find any DSP chip with serial LVDS interface and C66x core plus ARM core.
What are some good ways to build the signal processing part of the 24GHz Radar?
Thank you.
