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Increase decimation, remove filter

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This commit is contained in:
Jan Hamal Dvořák 2024-07-31 22:54:59 +02:00
parent 2068d3a01f
commit 71543c70da
1 changed files with 52 additions and 38 deletions
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90
src/main.c
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@ -51,9 +51,9 @@ static uint32_t lo_phase[LO_NUM_PHASES][LO_PHASE_WORDS]
static const uint32_t *lo_cos_phases[LO_COS_PHASES]
__attribute__((__aligned__(1 << LO_PHASE_BITS)));
#define DECIMATE 4
#define DECIMATE 16
#define RX_STRIDE (2 * IQ_SAMPLES * DECIMATE)
#define RX_BITS_DEPTH 13
#define RX_BITS_DEPTH 14
#define RX_WORDS (1 << (RX_BITS_DEPTH - 2))
static_assert(RX_STRIDE * 4 <= RX_WORDS, "RX_STRIDE * 4 <= RX_WORDS");
@ -434,47 +434,61 @@ struct IQ {
inline static struct IQ next_sample(const uint32_t *buf)
{
static int h[11];
int x3 = gain * (-2 * buf[0] - buf[1] - dc_level);
int x2 = gain * (-2 * buf[2] - buf[3] - dc_level);
int x1 = -(gain * (-2 * buf[4] - buf[5] - dc_level));
int x0 = -(gain * (-2 * buf[6] - buf[7] - dc_level));
const int c[] = { 4, 2, -8, -9, 19, 55 };
int x15 = gain * (-2 * buf[0] - buf[1] - dc_level);
int x14 = gain * (-2 * buf[2] - buf[3] - dc_level);
int x13 = gain * (-2 * buf[4] - buf[5] - dc_level);
int x12 = gain * (-2 * buf[6] - buf[7] - dc_level);
int x11 = gain * (-2 * buf[8] - buf[9] - dc_level);
int x10 = gain * (-2 * buf[10] - buf[11] - dc_level);
int x09 = gain * (-2 * buf[12] - buf[13] - dc_level);
int x08 = gain * (-2 * buf[14] - buf[15] - dc_level);
int x07 = gain * (-2 * buf[16] - buf[17] - dc_level);
int x06 = gain * (-2 * buf[18] - buf[19] - dc_level);
int x05 = gain * (-2 * buf[20] - buf[21] - dc_level);
int x04 = gain * (-2 * buf[22] - buf[23] - dc_level);
int x03 = gain * (-2 * buf[24] - buf[25] - dc_level);
int x02 = gain * (-2 * buf[26] - buf[27] - dc_level);
int x01 = gain * (-2 * buf[28] - buf[29] - dc_level);
int x00 = gain * (-2 * buf[30] - buf[31] - dc_level);
int I = 0, Q = 0;
Q += (c[0]) * h[10];
I += (c[0] + c[1]) * h[9];
Q += (c[0] + c[1] + c[2]) * h[8];
I += (c[0] + c[1] + c[2] + c[3]) * h[7];
Q += (c[1] + c[2] + c[3] + c[4]) * h[6];
I += (c[2] + c[3] + c[4] + c[5]) * h[5];
Q += (c[3] + c[4] + c[5] + c[5]) * h[4];
I += (c[4] + c[5] + c[5] + c[4]) * h[3];
Q += (c[5] + c[5] + c[4] + c[3]) * h[2];
I += (c[5] + c[4] + c[3] + c[2]) * h[1];
Q += (c[4] + c[3] + c[2] + c[1]) * h[0];
I += (c[3] + c[2] + c[1] + c[0]) * x3;
Q += (c[2] + c[1] + c[0]) * x2;
I += (c[1] + c[0]) * x1;
Q += (c[0]) * x0;
I += 93 * x15;
I += 71 * x14;
I += 39 * x13;
I += 0 * x12;
I += -39 * x11;
I += -71 * x10;
I += -93 * x09;
I += -101 * x08;
I += -93 * x07;
I += -71 * x06;
I += -39 * x05;
I += 0 * x04;
I += 39 * x03;
I += 71 * x02;
I += 93 * x01;
I += 101 * x00;
I /= 128;
Q /= 128;
Q += 39 * x15;
Q += 71 * x14;
Q += 93 * x13;
Q += 101 * x12;
Q += 93 * x11;
Q += 71 * x10;
Q += 39 * x09;
Q += 0 * x08;
Q += -39 * x07;
Q += -71 * x06;
Q += -93 * x05;
Q += -101 * x04;
Q += -93 * x03;
Q += -71 * x02;
Q += -39 * x01;
Q += 0 * x00;
h[10] = h[6];
h[9] = h[5];
h[8] = h[4];
h[7] = h[3];
h[6] = h[2];
h[5] = h[1];
h[4] = h[0];
h[3] = x3;
h[2] = x2;
h[1] = x1;
h[0] = x0;
I /= 1024;
Q /= 1024;
return (struct IQ){ I, Q };
}