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Comment by h0m3us3r | Hacker News Reader

Yes they are. And they have a much wider tuning range (I have one that tunes from 240 MHz to 7 GHz). Problem of standard hardware is that every path has dedicated SAW/BAW bandpass filters that yeet anything not in uplink/downlink. And you need an unfused chip for custom Hexagon DSP stuff (so no phones).

Base stations are also SDRs by the way xD

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Their DSP/SoC silicon includes a wideband transceiver? But phone chips have external bandpass filters? Interesting. Mostly I've seen baseband processor + external transceiver (wideband or not) with its own filters.

External transceiver over QLink.

I know the LTE modems had ADCs and DACs in SoC - ZIF with analog signal running straight between the tuner and the SoC. But 5G systems rolled ADC/DAC into the transceiver chip itself - with only the digital processing living in SoC.

Is the "QLink" setup they use in 5G systems now just a thin protocol running over LVDS and streaming I/Q between the transceiver and SoC DSP as digital signals?

Never actually went that far, but I did wonder if you could plug a QLink tuner chip into an FPGA to use it as a broadband SDR frontend.

There are also chips like NXP layerscape which do the sampling and hardware acceleration on a chip which streams to host (though still need another transceiver).

The motivation for this is of course beamforming, angle of arrival, spatial streaming, etc. You connect multiple antennas with different views back to the base station.

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