code.octet-stream.net Git - m17rt/blob - m17core/src/shaping.rs

   1 pub static RRC_48K: [f32; 81] = [
   2     -0.0031955054,
   3     -0.002930098,
   4     -0.001940547,
   5     -0.00035607078,
   6     0.0015469185,
   7     0.003389342,
   8     0.0047616027,
   9     0.0053105336,
  10     0.0048244493,
  11     0.003297721,
  12     0.00095865194,
  13     -0.0017498062,
  14     -0.00423843,
  15     -0.005881418,
  16     -0.006149877,
  17     -0.0047450834,
  18     -0.0017040828,
  19     0.0025476913,
  20     0.0072151264,
  21     0.011230345,
  22     0.013421123,
  23     0.012729687,
  24     0.008449026,
  25     0.00043672565,
  26     -0.010734711,
  27     -0.023725418,
  28     -0.03649577,
  29     -0.04649801,
  30     -0.0509759,
  31     -0.04733776,
  32     -0.03355284,
  33     -0.008513286,
  34     0.027694825,
  35     0.07365995,
  36     0.1266812,
  37     0.18297966,
  38     0.23806532,
  39     0.28721792,
  40     0.3260201,
  41     0.35087407,
  42     0.35943073,
  43     0.35087407,
  44     0.3260201,
  45     0.28721792,
  46     0.23806532,
  47     0.18297966,
  48     0.1266812,
  49     0.07365995,
  50     0.027694825,
  51     -0.008513286,
  52     -0.03355284,
  53     -0.04733776,
  54     -0.0509759,
  55     -0.04649801,
  56     -0.03649577,
  57     -0.023725418,
  58     -0.010734711,
  59     0.00043672565,
  60     0.008449026,
  61     0.012729687,
  62     0.013421123,
  63     0.011230345,
  64     0.0072151264,
  65     0.0025476913,
  66     -0.0017040828,
  67     -0.0047450834,
  68     -0.006149877,
  69     -0.005881418,
  70     -0.00423843,
  71     -0.0017498062,
  72     0.00095865194,
  73     0.003297721,
  74     0.0048244493,
  75     0.0053105336,
  76     0.0047616027,
  77     0.003389342,
  78     0.0015469185,
  79     -0.00035607078,
  80     -0.001940547,
  81     -0.002930098,
  82     -0.0031955054,
  83 ];
  84
  85 #[cfg(test)]
  86 mod test {
  87     use std::f32::consts::PI;
  88
  89     #[test]
  90     fn calculate_rrc_coefficients() {
  91         let mut rrc = [0.0; 81];
  92         let roll_off = 0.5;
  93         let t_s: f32 = 10.0;
  94
  95         let inf_t = t_s / (4.0 * roll_off);
  96
  97         for i in 0..81 {
  98             let t = (i as isize - 40) as f32;
  99
 100             if t == 0.0 {
 101                 rrc[i] = 1.0 / t_s.sqrt() * ((1.0 - roll_off) + (4.0 * roll_off / PI));
 102             } else if t == inf_t || t == -inf_t {
 103                 rrc[i] = roll_off / (2.0 * t_s).sqrt()
 104                     * ((1.0 + 2.0 / PI) * f32::sin(PI / (4.0 * roll_off))
 105                         + (1.0 - 2.0 / PI) * f32::cos(PI / (4.0 * roll_off)));
 106             } else {
 107                 rrc[i] = 1.0 / t_s.sqrt()
 108                     * (f32::sin((PI * t * (1.0 - roll_off)) / t_s)
 109                         + (4.0 * roll_off * t) / t_s * f32::cos((PI * t * (1.0 + roll_off)) / t_s))
 110                     / (PI * t / t_s * (1.0 - (4.0 * roll_off * t / t_s).powi(2)));
 111             }
 112         }
 113
 114         println!("{:?}", rrc);
 115         for (a, b) in rrc.iter().zip(super::RRC_48K.iter()) {
 116             assert!((a - b).abs() < 0.00001);
 117         }
 118     }
 119 }