Use code generation from GNSSSignals.jl (#29)

* Use `GNSSSignals.jl` for code calculation

* Increase minimum Julia version to 1.6

Co-authored-by: Soeren Schoenbrod <[email protected]>

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.4' # Replace this with the minimum Julia version that your package supports. E.g. if your package requires Julia 1.5 or higher, change this to '1.5'.
+          - '1.6' # Replace this with the minimum Julia version that your package supports. E.g. if your package requires Julia 1.5 or higher, change this to '1.5'.
           - '1' # Leave this line unchanged. '1' will automatically expand to the latest stable 1.x release of Julia.
           - 'nightly'
         os:

Project.toml

@@ -1,7 +1,7 @@
 name = "Tracking"
 uuid = "10b2438b-ffd4-5096-aa58-44041d5c8f3b"
 authors = ["Soeren Zorn <[email protected]>"]
-version = "0.14.6"
+version = "0.14.7"
 
 [deps]
 DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
@@ -15,13 +15,13 @@ Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 
 [compat]
 DocStringExtensions = "0.6, 0.7, 0.8"
-GNSSSignals = "0.15"
+GNSSSignals = "0.15.3"
 LoopVectorization = "0.8, 0.9, 0.10, 0.11, 0.12"
 StaticArrays = "0.9, 0.10, 0.11, 0.12, 1.0"
 StructArrays = "0.4"
 TrackingLoopFilters = "0.1"
 Unitful = "0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 1.0"
-julia = "1.4"
+julia = "1.6"
 
 [extras]
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"

src/code_replica.jl

@@ -1,13 +1,13 @@
 """
 $(SIGNATURES)
 
-Generate a code replica for a signal from satellite system `S`. The 
+Generate a code replica for a signal from satellite system `S`. The
 replica contains `num_samples` prompt samples as well as an additional
 number of early and late samples specified by `correlator_sample_shifts`.
 The codefrequency is specified by `code_frequency`, while the sampling
-rate is given by `sampling_frequency`. The phase of the first prompt 
+rate is given by `sampling_frequency`. The phase of the first prompt
 sample is given by `start_code_phase`. The generated signal is returned
-in the array `code_replica` with the first generated sample written to 
+in the array `code_replica` with the first generated sample written to
 index start_sample.
 """
 function gen_code_replica!(
@@ -23,20 +23,15 @@ function gen_code_replica!(
 )
     most_early_sample_shift = correlator_sample_shifts[end]
     most_late_sample_shift  = correlator_sample_shifts[1]
-    num_early_late_samples = most_early_sample_shift - most_late_sample_shift
-    fixed_point = sizeof(Int) * 8 - 1 - min_bits_for_code_length(system)
-    total_code_length = get_code_length(system) * get_secondary_code_length(system)
-    fixed_point_total_code_length = total_code_length * 1 << fixed_point
-    modded_start_code_phase = mod(start_code_phase, total_code_length)
-    fixed_point_start_code_phase = floor(Int, modded_start_code_phase * 1 << fixed_point)
-    delta = floor(Int, code_frequency * 1 << fixed_point / sampling_frequency)
-    fixed_point_code_phase = fixed_point_start_code_phase + (most_late_sample_shift - 1) * delta
-    @inbounds for i = start_sample:num_samples + num_early_late_samples + start_sample - 1
-        fixed_point_code_phase += delta
-        fixed_point_code_phase -= (fixed_point_code_phase >= fixed_point_total_code_length) * fixed_point_total_code_length
-        code_index = fixed_point_code_phase >> fixed_point
-        code_replica[i] = get_code_unsafe(system, code_index, prn)
-    end
+    total_samples = num_samples + most_early_sample_shift - most_late_sample_shift
+    gen_code!(
+        view(code_replica, start_sample:start_sample+total_samples-1),
+        system,
+        prn,
+        sampling_frequency,
+        code_frequency,
+        start_code_phase + most_late_sample_shift * code_frequency/sampling_frequency
+    )
     code_replica
 end
 
@@ -56,7 +51,7 @@ function update_code_phase(
     secondary_code_or_bit_length = get_data_frequency(system) == 0Hz ?
         get_secondary_code_length(system) :
         Int(get_code_frequency(system) / (get_data_frequency(system) * get_code_length(system)))
-        
+
     code_length = get_code_length(system) *
         (secondary_code_or_bit_found ? secondary_code_or_bit_length : 1)
     mod(code_frequency * num_samples / sampling_frequency + start_code_phase, code_length)

test/code_replica.jl

@@ -5,8 +5,8 @@
     Tracking.gen_code_replica!(
         code,
         gpsl1,
-        1023e3,
-        2.5e6,
+        1023e3Hz,
+        2.5e6Hz,
         2.0,
         11,
         2480,
@@ -22,8 +22,8 @@
         Tracking.gen_code_replica!(
             code,
             gpsl1,
-            1023e3,
-            2.5e6,
+            1023e3Hz,
+            2.5e6Hz,
             2.0,
             11,
             6480,
@@ -40,8 +40,8 @@
         Tracking.gen_code_replica!(
             code,
             gpsl1,
-            1023e3 * 3,
-            7.5e6,
+            1023e3Hz * 3,
+            7.5e6Hz,
             2.0,
             11,
             2480,

test/tracking_loop.jl

@@ -150,8 +150,8 @@ end
     gpsl1 = GPSL1()
     carrier_doppler = 200Hz
     start_code_phase = 100
-    code_frequency = carrier_doppler / 1540 + 1023kHz
-    sampling_frequency = 4MHz
+    code_frequency = carrier_doppler / 1540 + 1023e3Hz
+    sampling_frequency = 4e6Hz
     prn = 1
     range = 0:3999
     start_carrier_phase = π / 2
@@ -237,8 +237,8 @@ end
     gpsl1 = GPSL1()
     carrier_doppler = 200Hz
     start_code_phase = 100
-    code_frequency = carrier_doppler / 1540 + 1023kHz
-    sampling_frequency = 4MHz
+    code_frequency = carrier_doppler / 1540 + 1023e3Hz
+    sampling_frequency = 4e6Hz
     prn = 1
     range = 0:3999
     start_carrier_phase = π / 2