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Comment by kristoffer | Hacker News Reader

It is possible to do compliant LTE phy on x86, of course it is not so energy efficient. Also x86 + fpga SoC is coming soon and could be interesting for that kind of purpose. Though I don't think baseband virtualisation will be something big in the near future.

And LTE CC is not the necessarily a good way to get multi-Gbps due to radio complexity.

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I have seen such projects - real LTE PHY algorithms are much more complex than stuff in 3GPP. You can write something 3GPP compliant in some simplified cases, but it would be totally useless in real network.

Secondly you don't really want to use FPGA for majority DSP processing in LTE PHY. Design cycles on FPGA are too slow and HLS techniques are still not trusted. Beside that x86+fpga are some kind of specialized stuff - you could just put a PCIe accelerator with some major wireless SoC.

Modern x86 is quite competent as DSP using AVX. I think you are exaggerating. I have worked with LTE baseband as well, but admittedly never done an x86 LTE PHY. pCell claims to be doing quite complex network mimo LTE stuff on x86, still mostly vaporware though.

Regarding FPGA, of course you don't do the complete implementation in it, you accelerate the low level stuff, FFTs, coding, etc, as are already done in all baseband dsps.

Yep, AVX is nice, but still it is far from current DSP chips. I ported a subset of PHY to real AVX2 CPU and AVX512 sim. It is (sometimes) comparable to c6x (which is a crap DSP) if you take (much) higher clock into account, but comparing to current DSP IP cores it is a joke.

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