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will this work?

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This commit is contained in:
KubaPro010
2025-04-28 16:20:25 +02:00
parent cac63033bc
commit 6e1a52cacb
5 changed files with 17 additions and 44 deletions
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2
.vscode/.server-controller-port.log vendored
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@@ -1,5 +1,5 @@
{
"port": 13452,
"time": 1745432304494,
"time": 1745844256741,
"version": "0.0.3"
}

53
gen_wave.py
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@@ -7,7 +7,7 @@ if PLOT: import matplotlib.pyplot as plt
if FFT: import numpy as np
DATA_RATE = 1187.5
SIZE_RATIO = 2
SIZE_RATIO = 1
ratio = 16
sample_rate = DATA_RATE*ratio
@@ -23,17 +23,12 @@ def rrcosfilter(NumSamples):
for x in sample_num:
t = (x-NumSamples/2)*T_delta
if t == 0.0:
h_rrc[x] = 1.0 - 1 + (4/math.pi)
elif t == SymbolPeriod/4:
h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi)* \
(math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
elif t == -SymbolPeriod/4:
h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi)* \
(math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
else:
h_rrc[x] = (4*(t/SymbolPeriod)*math.cos(math.pi*t*2/SymbolPeriod))/ \
(math.pi*t*(1-(4*t/SymbolPeriod)*(4*t/SymbolPeriod))/SymbolPeriod)
if t == 0.0: h_rrc[x] = 1.0 - 1 + (4/math.pi)
elif t == SymbolPeriod/4: h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi) * (math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
elif t == -SymbolPeriod/4: h_rrc[x] = (1/math.sqrt(2))*(((1+2/math.pi) * (math.sin(math.pi/4))) + ((1-2/math.pi)*(math.cos(math.pi/4))))
else: h_rrc[x] = (4*(t/SymbolPeriod)*math.cos(math.pi*t*2/SymbolPeriod)) / (math.pi*t*(1-(4*t/SymbolPeriod)*(4*t/SymbolPeriod))/SymbolPeriod)
blackman = [0.42 + 0.5*math.cos(math.pi*i/(NumSamples-1)) + 0.08*math.cos(2.0*math.pi*i/(NumSamples-1)) for i in range(NumSamples)]
h_rrc = [h_rrc[i] * blackman[i] for i in range(NumSamples)]
return h_rrc
@@ -63,36 +58,14 @@ outc.write(header)
outh.write(header)
def generate():
l = ratio // 2
sample = [0.0] * (16*l)
sample[l] = 1
sample[2*l] = -1
sf = rrcosfilter(l*16)
shapedSamples = convolve(sample, sf)
lowest = 0
lowest_idx = 0
highest = 0
highest_idx = 0
for i,j in enumerate(shapedSamples):
if j < lowest:
lowest = j
lowest_idx = i
if j > highest:
highest = j
highest_idx = i
middle = int((lowest_idx+highest_idx)/2)
out = shapedSamples[middle-int(ratio*SIZE_RATIO):middle+int(ratio*SIZE_RATIO)]
out = [2 * (i - min(out)) / (max(out) - min(out)) - 1 for i in out]
if max(out) > 1 or min(out) < -1: raise Exception("Clipped")
print(f"{len(out)=} {len(out)/sample_rate=} {(len(out)/sample_rate)/(1/DATA_RATE)=} {1/DATA_RATE=}")
t = [i / sample_rate for i in range(ratio)]
out = [math.sin(2 * math.pi * DATA_RATE * time) for time in t]
print(f"{len(out)=} {len(out)/sample_rate=} {1/DATA_RATE=}")
if PLOT:
plt.plot(out, label="out")
plt.plot(out*4, label="out")
plt.legend()
plt.axvline(x=len(out)*2, color='r', linestyle='--', label='center')
plt.grid(True)
plt.show()
@@ -103,7 +76,7 @@ def generate():
plt.figure(figsize=(10, 6))
plt.plot(fft_freqs[:N//2], np.abs(fft_out)[:N//2])
plt.xlim(0,DATA_RATE*3)
plt.xlim(0,DATA_RATE*2.5)
plt.title("FFT of the waveform")
plt.xlabel("Frequency (Hz)")
plt.ylabel("Magnitude")

2
src/rds.h
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@@ -12,7 +12,7 @@
#define BITS_PER_GROUP (GROUP_LENGTH * (BLOCK_SIZE + POLY_DEG))
#define RDS_SAMPLE_RATE 19000
#define SAMPLES_PER_BIT 16
#define FILTER_SIZE 64
#define FILTER_SIZE 16
#define SAMPLE_BUFFER_SIZE (SAMPLES_PER_BIT + FILTER_SIZE)
#define STREAMS 2

2
src/waveforms.c
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@@ -6,5 +6,5 @@
Released under the GNU GPL v3 license.
*/
float waveform_biphase[64] = {0.001905215527506554, 0.0014857449947831558, 0.0, -0.0018260510389287443, -0.002879473467708782, -0.0022799681256350235, 0.0, 0.0028998088186253934, 0.004662004662004504, 0.003770143371148116, 0.0, -0.005034068109133871, -0.008325008325008265, -0.006947655510042394, 0.0, 0.01000275871035683, 0.017316017316017396, 0.015236086644829783, 0.0, -0.025132981969720025, -0.04761904761904756, -0.046927146866075575, 0.0, 0.11019845940569595, 0.2857142857142856, 0.5076664070057264, 0.7363107781851077, 0.9183204950474642, 1.0, 0.9428090415820631, 0.7363107781851077, 0.4040610178208841, 0.0, -0.4040610178208842, -0.7363107781851077, -0.9428090415820631, -1.0, -0.918320495047464, -0.7363107781851077, -0.5076664070057264, -0.2857142857142857, -0.11019845940569584, 0.0, 0.046927146866075464, 0.04761904761904745, 0.025132981969720136, 0.0, -0.015236086644829672, -0.017316017316017285, -0.010002758710356718, 0.0, 0.006947655510042505, 0.008325008325008376, 0.005034068109133871, 0.0, -0.003770143371148116, -0.004662004662004615, -0.0028998088186253934, 0.0, 0.0022799681256351345, 0.002879473467708893, 0.0018260510389287443, 0.0, -0.0014857449947831558};
float waveform_biphase[16] = {0.0, 0.3826834323650898, 0.7071067811865475, 0.9238795325112867, 1.0, 0.9238795325112867, 0.7071067811865476, 0.3826834323650899, 1.2246467991473532e-16, -0.3826834323650892, -0.7071067811865475, -0.9238795325112868, -1.0, -0.923879532511287, -0.7071067811865477, -0.3826834323650904};

2
src/waveforms.h
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@@ -6,4 +6,4 @@
Released under the GNU GPL v3 license.
*/
extern float waveform_biphase[64];
extern float waveform_biphase[16];