yagi 0.1.3

Batteries-included DSP library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389

use crate::error::{Error, Result};
use crate::utility::bits::{bdotprod, msb_index};

const MIN_MSEQUENCE_M: u32 = 2;
const MAX_MSEQUENCE_M: u32 = 31;

// default m-sequence generators:       g (hex)            m   n
const MSEQUENCE_GENPOLY_M2: u32 = 0x00000003;   //  2   3
const MSEQUENCE_GENPOLY_M3: u32 = 0x00000006;   //  3   7
const MSEQUENCE_GENPOLY_M4: u32 = 0x0000000c;   //  4   15
const MSEQUENCE_GENPOLY_M5: u32 = 0x00000014;   //  5   31
const MSEQUENCE_GENPOLY_M6: u32 = 0x00000030;   //  6   63
const MSEQUENCE_GENPOLY_M7: u32 = 0x00000060;   //  7   127
const MSEQUENCE_GENPOLY_M8: u32 = 0x000000b8;   //  8   255
const MSEQUENCE_GENPOLY_M9: u32 = 0x00000110;   //  9   511
const MSEQUENCE_GENPOLY_M10: u32 = 0x00000240;  // 10   1,023
const MSEQUENCE_GENPOLY_M11: u32 = 0x00000500;  // 11   2,047
const MSEQUENCE_GENPOLY_M12: u32 = 0x00000e08;  // 12   4,095
const MSEQUENCE_GENPOLY_M13: u32 = 0x00001c80;  // 13   8,191
const MSEQUENCE_GENPOLY_M14: u32 = 0x00003802;  // 14   16,383
const MSEQUENCE_GENPOLY_M15: u32 = 0x00006000;  // 15   32,767
const MSEQUENCE_GENPOLY_M16: u32 = 0x0000d008;  // 16   65,535
const MSEQUENCE_GENPOLY_M17: u32 = 0x00012000;  // 17   131,071
const MSEQUENCE_GENPOLY_M18: u32 = 0x00020400;  // 18   262,143
const MSEQUENCE_GENPOLY_M19: u32 = 0x00072000;  // 19   524,287
const MSEQUENCE_GENPOLY_M20: u32 = 0x00090000;  // 20   1,048,575
const MSEQUENCE_GENPOLY_M21: u32 = 0x00140000;  // 21   2,097,151
const MSEQUENCE_GENPOLY_M22: u32 = 0x00300000;  // 22   4,194,303
const MSEQUENCE_GENPOLY_M23: u32 = 0x00420000;  // 23   8,388,607
const MSEQUENCE_GENPOLY_M24: u32 = 0x00e10000;  // 24   16,777,215
const MSEQUENCE_GENPOLY_M25: u32 = 0x01000004;  // 25   33,554,431
const MSEQUENCE_GENPOLY_M26: u32 = 0x02000023;  // 26   67,108,863
const MSEQUENCE_GENPOLY_M27: u32 = 0x04000013;  // 27   134,217,727
const MSEQUENCE_GENPOLY_M28: u32 = 0x08000004;  // 28   268,435,455
const MSEQUENCE_GENPOLY_M29: u32 = 0x10000002;  // 29   536,870,911
const MSEQUENCE_GENPOLY_M30: u32 = 0x20000029;  // 30   1,073,741,823
const MSEQUENCE_GENPOLY_M31: u32 = 0x40000004;  // 31   2,147,483,647

/// maximal-length sequence
#[derive(Debug, Clone, Copy)]
pub struct MSequence {
    m: u32,     // length generator polynomial, shift register
    g: u32,     // generator polynomial, form: { x^m + ... + 1 }
    a: u32,     // initial shift register state, default: 1
    n: u32,     // length of sequence, n = (2^m)-1
    state: u32, // shift register
}

impl MSequence {
    /// create a maximal-length sequence (m-sequence) object with
    /// an internal shift register length of _m bits.
    ///  m      :   generator polynomial length, sequence length is (2^m)-1
    ///  g      :   generator polynomial, starting with most-significant bit
    ///  a      :   initial shift register state, default: 000...001
    pub fn new(m: u32, g: u32, a: u32) -> Result<Self> {
        if m > MAX_MSEQUENCE_M || m < MIN_MSEQUENCE_M {
            return Err(Error::Config(format!("m ({}) not in range", m)));
        }

        Ok(Self {
            m,
            g,
            a,
            n: (1 << m) - 1,
            state: a,
        })
    }

    pub fn create_genpoly(g: u32) -> Result<Self> {
        let t = msb_index(g);
        if t < 2 {
            return Err(Error::Config(format!("invalid generator polynomial: 0x{:x}", g)));
        }
        let m = t;
        let a = 1;
        Self::new(m, g, a)
    }

    pub fn create_default(m: u32) -> Result<Self> {
        let g = match m {
            2 => MSEQUENCE_GENPOLY_M2,
            3 => MSEQUENCE_GENPOLY_M3,
            4 => MSEQUENCE_GENPOLY_M4,
            5 => MSEQUENCE_GENPOLY_M5,
            6 => MSEQUENCE_GENPOLY_M6,
            7 => MSEQUENCE_GENPOLY_M7,
            8 => MSEQUENCE_GENPOLY_M8,
            9 => MSEQUENCE_GENPOLY_M9,
            10 => MSEQUENCE_GENPOLY_M10,
            11 => MSEQUENCE_GENPOLY_M11,
            12 => MSEQUENCE_GENPOLY_M12,
            13 => MSEQUENCE_GENPOLY_M13,
            14 => MSEQUENCE_GENPOLY_M14,
            15 => MSEQUENCE_GENPOLY_M15,
            16 => MSEQUENCE_GENPOLY_M16,
            17 => MSEQUENCE_GENPOLY_M17,
            18 => MSEQUENCE_GENPOLY_M18,
            19 => MSEQUENCE_GENPOLY_M19,
            20 => MSEQUENCE_GENPOLY_M20,
            21 => MSEQUENCE_GENPOLY_M21, 
            22 => MSEQUENCE_GENPOLY_M22,
            23 => MSEQUENCE_GENPOLY_M23,
            24 => MSEQUENCE_GENPOLY_M24,
            25 => MSEQUENCE_GENPOLY_M25,
            26 => MSEQUENCE_GENPOLY_M26,
            27 => MSEQUENCE_GENPOLY_M27,
            28 => MSEQUENCE_GENPOLY_M28,
            29 => MSEQUENCE_GENPOLY_M29,
            30 => MSEQUENCE_GENPOLY_M30,
            31 => MSEQUENCE_GENPOLY_M31,
            _ => return Err(Error::Config(format!("m ({}) not in range", m))),
        };
        Self::create_genpoly(g)
    }

    pub fn advance(&mut self) -> u32 {
        let b = bdotprod(self.state, self.g);
        self.state <<= 1;
        self.state |= b;
        self.state &= self.n;
        b
    }

    pub fn generate_symbol(&mut self, bps: u32) -> u32 {
        let mut s = 0;
        for _ in 0..bps {
            s <<= 1;
            s |= self.advance();
        }
        s
    }

    pub fn reset(&mut self) {
        self.state = self.a;
    }

    /// Getter methods
    pub fn get_genpoly_length(&self) -> u32 { self.m }
    pub fn get_length(&self) -> u32 { self.n }
    pub fn get_genpoly(&self) -> u32 { self.g }
    pub fn get_state(&self) -> u32 { self.state }

    pub fn set_state(&mut self, a: u32) {
        self.state = a;
    }

    pub fn measure_period(&mut self) -> u32 {
        let s = self.get_state();
        let mut period = 0;
        for _ in 0..=self.n {
            self.advance();
            period += 1;
            if self.get_state() == s {
                break;
            }
        }
        period
    }

    pub fn genpoly_period(g: u32) -> Result<u32> {
        let mut q = MSequence::create_genpoly(g)?;
        Ok(q.measure_period())
    }
}

#[cfg(test)]
mod tests{
    use super::*;
    use test_macro::autotest_annotate;

    use crate::sequence::bsequence::BSequence;

    fn msequence_test_autocorrelation(m: u32) {
        // create and initialize m-sequence
        let mut ms = MSequence::create_default(m).unwrap();
        let n = ms.get_length();

        // create and initialize first binary sequence on m-sequence
        let bs1 = BSequence::from_msequence(&mut ms).unwrap();

        // create and initialize second binary sequence on same m-sequence
        let mut bs2 = BSequence::from_msequence(&mut ms).unwrap();

        // ensure sequences are the same length
        assert_eq!(bs1.get_length(), n as usize);
        assert_eq!(bs2.get_length(), n as usize);

        // when sequences are aligned, autocorrelation is equal to length
        let mut rxy = bs1.correlate(&bs2).unwrap();
        assert_eq!(rxy, n as i32);

        // when sequences are misaligned, autocorrelation is equal to -1
        for _ in 0..n-1 {
            bs2.push(ms.advance());
            rxy = 2 * bs1.correlate(&bs2).unwrap() - n as i32;
            assert_eq!(rxy, -1);
        }
    }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m2)]
    fn test_msequence_xcorr_m2() { msequence_test_autocorrelation(2); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m3)]
    fn test_msequence_xcorr_m3() { msequence_test_autocorrelation(3); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m4)]
    fn test_msequence_xcorr_m4() { msequence_test_autocorrelation(4); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m5)]
    fn test_msequence_xcorr_m5() { msequence_test_autocorrelation(5); }

    #[test] 
    #[autotest_annotate(autotest_msequence_xcorr_m6)]
    fn test_msequence_xcorr_m6() { msequence_test_autocorrelation(6); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m7)]
    fn test_msequence_xcorr_m7() { msequence_test_autocorrelation(7); }
    
    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m8)]
    fn test_msequence_xcorr_m8() { msequence_test_autocorrelation(8); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m9)]
    fn test_msequence_xcorr_m9() { msequence_test_autocorrelation(9); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m10)]
    fn test_msequence_xcorr_m10() { msequence_test_autocorrelation(10); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m11)]
    fn test_msequence_xcorr_m11() { msequence_test_autocorrelation(11); }

    #[test]
    #[autotest_annotate(autotest_msequence_xcorr_m12)]
    fn test_msequence_xcorr_m12() { msequence_test_autocorrelation(12); }

    fn msequence_test_period(m: u32) {
        // create and initialize m-sequence
        let mut q = MSequence::create_default(m).unwrap();

        // measure period and compare to expected
        let n = (1u32 << m) - 1;
        let p = q.measure_period();
        assert_eq!(p, n);
    }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m2)]
    fn test_msequence_period_m2() { msequence_test_period(2); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m3)]
    fn test_msequence_period_m3() { msequence_test_period(3); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m4)]
    fn test_msequence_period_m4() { msequence_test_period(4); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m5)]
    fn test_msequence_period_m5() { msequence_test_period(5); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m6)]
    fn test_msequence_period_m6() { msequence_test_period(6); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m7)]
    fn test_msequence_period_m7() { msequence_test_period(7); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m8)]
    fn test_msequence_period_m8() { msequence_test_period(8); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m9)]
    fn test_msequence_period_m9() { msequence_test_period(9); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m10)]
    fn test_msequence_period_m10() { msequence_test_period(10); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m11)]
    fn test_msequence_period_m11() { msequence_test_period(11); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m12)]
    fn test_msequence_period_m12() { msequence_test_period(12); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m13)]
    fn test_msequence_period_m13() { msequence_test_period(13); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m14)]
    fn test_msequence_period_m14() { msequence_test_period(14); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m15)]
    fn test_msequence_period_m15() { msequence_test_period(15); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m16)]
    fn test_msequence_period_m16() { msequence_test_period(16); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m17)]
    fn test_msequence_period_m17() { msequence_test_period(17); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m18)]
    fn test_msequence_period_m18() { msequence_test_period(18); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m19)]
    fn test_msequence_period_m19() { msequence_test_period(19); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m20)]
    fn test_msequence_period_m20() { msequence_test_period(20); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m21)]
    fn test_msequence_period_m21() { msequence_test_period(21); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m22)]
    fn test_msequence_period_m22() { msequence_test_period(22); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m23)]
    fn test_msequence_period_m23() { msequence_test_period(23); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m24)]
    fn test_msequence_period_m24() { msequence_test_period(24); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m25)]
    fn test_msequence_period_m25() { msequence_test_period(25); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m26)]
    fn test_msequence_period_m26() { msequence_test_period(26); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m27)]
    fn test_msequence_period_m27() { msequence_test_period(27); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m28)]
    fn test_msequence_period_m28() { msequence_test_period(28); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m29)]
    fn test_msequence_period_m29() { msequence_test_period(29); }
        
    #[test]
    #[autotest_annotate(autotest_msequence_period_m30)]
    fn test_msequence_period_m30() { msequence_test_period(30); }

    #[test]
    #[autotest_annotate(autotest_msequence_period_m31)]
    fn test_msequence_period_m31() { msequence_test_period(31); }

    #[test]
    #[autotest_annotate(autotest_msequence_config)]
    fn test_msequence_config() {
        // check invalid configurations
        assert!(MSequence::new(100, 0, 0).is_err());
        assert!(MSequence::create_default(32).is_err()); // too long
        assert!(MSequence::create_genpoly(0).is_err());

        // create proper object and test configurations
        let mut q = MSequence::create_genpoly(MSEQUENCE_GENPOLY_M11).unwrap();

        assert_eq!(q.get_state(), 1);
        q.set_state(0x8a);
        assert_eq!(q.get_state(), 0x8a);
    }
}