* Generate Qm LLRS for Qm==8 * Modulation, AWGN and LLR estimation from max log development */
| 1557 | * Modulation, AWGN and LLR estimation from max log development |
| 1558 | */ |
| 1559 | static void |
| 1560 | gen_qm8_llr(int8_t *llrs, uint32_t i, double N0, double llr_max) |
| 1561 | { |
| 1562 | int qm = 8; |
| 1563 | int qam = 256; |
| 1564 | int m, k; |
| 1565 | double I, Q, p0, p1, llr_, b[qm], log_syml_prob[qam]; |
| 1566 | /* 5.1.4 of TS38.211 */ |
| 1567 | const double symbols_I[256] = { |
| 1568 | 5, 5, 7, 7, 5, 5, 7, 7, 3, 3, 1, 1, 3, 3, 1, 1, 5, |
| 1569 | 5, 7, 7, 5, 5, 7, 7, 3, 3, 1, 1, 3, 3, 1, 1, 11, |
| 1570 | 11, 9, 9, 11, 11, 9, 9, 13, 13, 15, 15, 13, 13, |
| 1571 | 15, 15, 11, 11, 9, 9, 11, 11, 9, 9, 13, 13, 15, |
| 1572 | 15, 13, 13, 15, 15, 5, 5, 7, 7, 5, 5, 7, 7, 3, 3, |
| 1573 | 1, 1, 3, 3, 1, 1, 5, 5, 7, 7, 5, 5, 7, 7, 3, 3, 1, |
| 1574 | 1, 3, 3, 1, 1, 11, 11, 9, 9, 11, 11, 9, 9, 13, 13, |
| 1575 | 15, 15, 13, 13, 15, 15, 11, 11, 9, 9, 11, 11, 9, 9, |
| 1576 | 13, 13, 15, 15, 13, 13, 15, 15, -5, -5, -7, -7, -5, |
| 1577 | -5, -7, -7, -3, -3, -1, -1, -3, -3, -1, -1, -5, -5, |
| 1578 | -7, -7, -5, -5, -7, -7, -3, -3, -1, -1, -3, -3, |
| 1579 | -1, -1, -11, -11, -9, -9, -11, -11, -9, -9, -13, |
| 1580 | -13, -15, -15, -13, -13, -15, -15, -11, -11, -9, |
| 1581 | -9, -11, -11, -9, -9, -13, -13, -15, -15, -13, |
| 1582 | -13, -15, -15, -5, -5, -7, -7, -5, -5, -7, -7, -3, |
| 1583 | -3, -1, -1, -3, -3, -1, -1, -5, -5, -7, -7, -5, -5, |
| 1584 | -7, -7, -3, -3, -1, -1, -3, -3, -1, -1, -11, -11, |
| 1585 | -9, -9, -11, -11, -9, -9, -13, -13, -15, -15, -13, |
| 1586 | -13, -15, -15, -11, -11, -9, -9, -11, -11, -9, -9, |
| 1587 | -13, -13, -15, -15, -13, -13, -15, -15}; |
| 1588 | const double symbols_Q[256] = { |
| 1589 | 5, 7, 5, 7, 3, 1, 3, 1, 5, 7, 5, 7, 3, 1, 3, 1, 11, |
| 1590 | 9, 11, 9, 13, 15, 13, 15, 11, 9, 11, 9, 13, 15, 13, |
| 1591 | 15, 5, 7, 5, 7, 3, 1, 3, 1, 5, 7, 5, 7, 3, 1, 3, 1, |
| 1592 | 11, 9, 11, 9, 13, 15, 13, 15, 11, 9, 11, 9, 13, |
| 1593 | 15, 13, 15, -5, -7, -5, -7, -3, -1, -3, -1, -5, |
| 1594 | -7, -5, -7, -3, -1, -3, -1, -11, -9, -11, -9, -13, |
| 1595 | -15, -13, -15, -11, -9, -11, -9, -13, -15, -13, |
| 1596 | -15, -5, -7, -5, -7, -3, -1, -3, -1, -5, -7, -5, |
| 1597 | -7, -3, -1, -3, -1, -11, -9, -11, -9, -13, -15, |
| 1598 | -13, -15, -11, -9, -11, -9, -13, -15, -13, -15, 5, |
| 1599 | 7, 5, 7, 3, 1, 3, 1, 5, 7, 5, 7, 3, 1, 3, 1, 11, |
| 1600 | 9, 11, 9, 13, 15, 13, 15, 11, 9, 11, 9, 13, 15, |
| 1601 | 13, 15, 5, 7, 5, 7, 3, 1, 3, 1, 5, 7, 5, 7, 3, 1, |
| 1602 | 3, 1, 11, 9, 11, 9, 13, 15, 13, 15, 11, 9, 11, 9, |
| 1603 | 13, 15, 13, 15, -5, -7, -5, -7, -3, -1, -3, -1, |
| 1604 | -5, -7, -5, -7, -3, -1, -3, -1, -11, -9, -11, -9, |
| 1605 | -13, -15, -13, -15, -11, -9, -11, -9, -13, -15, |
| 1606 | -13, -15, -5, -7, -5, -7, -3, -1, -3, -1, -5, -7, |
| 1607 | -5, -7, -3, -1, -3, -1, -11, -9, -11, -9, -13, -15, |
| 1608 | -13, -15, -11, -9, -11, -9, -13, -15, -13, -15}; |
| 1609 | /* Average constellation point energy */ |
| 1610 | N0 *= 170.0; |
| 1611 | for (k = 0; k < qm; k++) |
| 1612 | b[k] = llrs[qm * i + k] < 0 ? 1.0 : 0.0; |
| 1613 | /* 5.1.4 of TS38.211 */ |
| 1614 | I = (1 - 2 * b[0]) * (8 - (1 - 2 * b[2]) * |
| 1615 | (4 - (1 - 2 * b[4]) * (2 - (1 - 2 * b[6])))); |
| 1616 | Q = (1 - 2 * b[1]) * (8 - (1 - 2 * b[3]) * |
no test coverage detected