Decoding GPS signal with GO (part 3)

Sun, 17 May 2026 11:15:03 +0200

In the last article, we saw how to catch the satellite’s signal using our gold codes and some trickery to handle their movements in the sky using Doppler compensation and phase shifting. However, this comes at a cost. It’s slow as hell. And we need to improve this if we want to decode our packets fast.

The Need for Speed (Acquisition Optimization)

First, let’s benchmark the first version:

for { 
 now := time.Now() 
 ... 
 
 for prn := 1; prn <= 32; prn++ { 
 bestPhase, bestDoppler, snr := gps.Acquire(outputComplex, prn, sampleRate) 
		...
 } 
 
 log.Printf("Processing took %v\n", time.Since(now)) 
}

$ make run
go build -o bin/gps-decoder cmd/gps-decoder/main.go
./bin/gps-decoder
Satellite PRN 05 found ! Phase: 792 | Doppler: -5000.00 | SNR: 8.71
Satellite PRN 14 found ! Phase: 636 | Doppler: -2000.00 | SNR: 12.41
Satellite PRN 15 found ! Phase: 587 | Doppler: 4000.00 | SNR: 11.78
Satellite PRN 20 found ! Phase: 906 | Doppler: 0.00 | SNR: 16.16
Satellite PRN 22 found ! Phase: 1140 | Doppler: 0.00 | SNR: 13.52
Satellite PRN 24 found ! Phase: 1168 | Doppler: 5000.00 | SNR: 8.11
Processing took 52.352300506s

Goroutines to the rescue

Alright, 52 seconds on an AMD Ryzen 7 PRO 6850U with 8 cores and 16 threads is slow. So now we will run the acquire method concurrently. To do so, we will define a struct for our acquisition data and then distribute them on a channel for later use. This way, we will use all of our cores.

Dsp on Dayio.dev

Decoding GPS signal with GO (part 3)

The Need for Speed (Acquisition Optimization)

Goroutines to the rescue