# Copyright (c) IMToolkit Development Team
# This toolkit is released under the MIT License, see LICENSE.txt
import numpy as np
from .Modulator import PSK, StarQAM
[docs]class TASTCode(object):
"""Differential space-time shift keying using threaded algebraic space-time (DSTSK-TAST) coding, which was proposed in [1]. Other relevant papers are found in [2,3].
- [1] C. Xu, P. Zhang, R. Rajashekar, N. Ishikawa, S. Sugiura, L. Wang, and L. Hanzo, ``Finite-cardinality single-RF differential space-time modulation for improving the diversity-throughput tradeoff,'' IEEE Trans. Commun. Press, vol. 67, no. 1, pp. 318--335, 2019.
- [2] C. Xu, R. Rajashekar, N. Ishikawa, S. Sugiura, and L. Hanzo, ``Single-RF index shift keying aided differential space-time block coding,'' IEEE Trans. Signal Process., vol. 66, no. 3, pp. 773--788, 2018.
- [3] C. Xu, P. Zhang, R. Rajashekar, N. Ishikawa, S. Sugiura, Z. Wang, and L. Hanzo, ````Near-perfect'' finite-cardinality generalized space-time shift keying,'' IEEE J. Sel. Areas Commun., in press.
"""
def __init__(self, M, Q, L, modtype = "SQAM"):
"""
Args:
M (int): the number of transmit antennas.
Q (int): the number of dispersion elements.
L (int): the constellation size.
modtype (str): the constellation type.
"""
self.M = M
self.Nc = M * L * Q
self.B = np.log2(self.Nc)
if modtype == "SQAM":
mod = StarQAM(L)
La = mod.Nlevels
Lp = mod.subConstellationSize
elif modtype == "PSK":
mod = PSK(L)
La = 1
Lp = L
apsksymbols = mod.symbols
G = np.zeros((M, M), dtype=np.complex)
G[0, M - 1] = 1
for m in range(M - 1):
G[m + 1, m] = 1
msymbols = np.exp(1j * 2.0 * np.pi * np.arange(M) / (Lp * np.max([M, Q])))
u = self.getDiversityMaximizingFactors(M, Q, La, Lp)
self.codes = np.zeros((M * L * Q, M, M), dtype=np.complex)
for l in range(L):
for m in range(M):
for q in range(Q):
qsymbols = np.exp(1j * 2.0 * np.pi * q * u * np.arange(M) / (L * Q))
self.codes[Q * M * l + m * Q + q] = np.matmul(
apsksymbols[l] * msymbols[m] * np.linalg.matrix_power(G, m), np.diag(qsymbols))
[docs] def putRate(self):
print("B / M = %d / %d = %d [bit/symbol]" % (self.B, self.M, self.B / self.M))
[docs] def getDiversityMaximizingFactors(self, M, Q, La, Lp):
if M == 2 and Q == 1 and La == 1 and Lp == 2:
# Rate = 1
u = [1, 1]
elif M == 2 and Q == 2 and La == 1 and Lp == 2:
# Rate = 1.5
u = [1, 3]
elif M == 2 and Q == 4 and La == 1 and Lp == 2:
# Rate = 2
u = [1, 3]
elif M == 2 and Q == 2 and La == 1 and Lp == 8:
# Rate = 2.5
# u = [1,7] [1, p. 22]
# u = [3,13] [1, p. 26]
u = [15, 5]
elif M == 2 and Q == 2 and La == 2 and Lp == 8:
# Rate = 3
# u = [3,13] # [1, p. 22]
u = [2, 14]
elif M == 2 and Q == 4 and La == 1 and Lp == 8:
# Rate = 3
u = [1, 7]
elif M == 2 and Q == 4 and La == 2 and Lp == 8:
# Rate = 3.5
u = [29, 3]
elif M == 2 and Q == 4 and La == 1 and Lp == 16:
# Rate = 3.5
u = [21, 59]
elif M == 2 and Q == 4 and La == 4 and Lp == 8: # Rate = 4, maxp = 0.080042
u = [29, 3]
elif M == 2 and Q == 8 and La == 2 and Lp == 8: # Rate = 4, maxp = 0.0957012
u = [53, 27]
elif M == 2 and Q == 16 and La == 1 and Lp == 8: # Rate = 4, maxp = 0.109983
u = [51, 81]
elif M == 2 and Q == 8 and La == 1 and Lp == 16: # Rate = 4, maxp = 0.140074
u = [3, 117]
elif M == 2 and Q == 4 and La == 4 and Lp == 16: # Rate = 4.5
u = [7, 57]
elif M == 2 and Q == 8 and La == 4 and Lp == 16: # rate = 5, maxp = 0.0511476
u = [108, 52]
elif M == 2 and Q == 16 and La == 4 and Lp == 8: # rate = 5, maxp = 0.04216
u = [39, 12]
elif M == 2 and Q == 32 and La == 2 and Lp == 8: # rate = 5, maxp = 0.0483617
u = [242, 46]
elif M == 2 and Q == 8 and La == 8 and Lp == 16: # Rate = 5.5
u = [3, 117]
elif M == 2 and Q == 8 and La == 8 and Lp == 32: # Rate = 6
u = [11, 237]
elif M == 4 and Q == 1 and La == 1 and Lp == 2: # Rate = 0.75
u = [1, 1, 1, 1]
elif M == 4 and Q == 2 and La == 1 and Lp == 2: # Rate = 1
u = [1, 1, 3, 3]
elif M == 4 and Q == 2 and La == 1 and Lp == 4: # Rate = 1.25
u = [1, 3, 7, 5]
elif M == 4 and Q == 2 and La == 1 and Lp == 8: # Rate = 1.5
# u = [1,3,7,9]
u = [1, 5, 11, 15]
elif M == 4 and Q == 4 and La == 1 and Lp == 8: # Rate = 1.75
# u = [9,21,15,27]
u = [5, 25, 11, 31]
elif M == 4 and Q == 1 and La == 4 and Lp == 16: # rate = 2, maxp = 0.0712369
u = [0, 0, 0, 0]
elif M == 4 and Q == 1 and La == 1 and Lp == 64: # rate = 2, maxp = 0.0490677
u = [0, 0, 0, 0]
elif M == 4 and Q == 2 and La == 4 and Lp == 8: # rate = 2, maxp = 0.0969766
u = [2, 13, 3, 14]
elif M == 4 and Q == 2 and La == 1 and Lp == 32: # rate = 2, maxp = 0.0980171
u = [59, 31, 49, 41]
elif M == 4 and Q == 4 and La == 2 and Lp == 8: # rate = 2, maxp = 0.214639
u = [21, 3, 29, 11]
elif M == 4 and Q == 4 and La == 1 and Lp == 16: # rate = 2, maxp = 0.19509
u = [37, 27, 11, 21]
elif M == 4 and Q == 8 and La == 2 and Lp == 4: # rate = 2, maxp = 0.199766
u = [26, 9, 31, 14]
elif M == 4 and Q == 8 and La == 1 and Lp == 8: # rate = 2, maxp = 0.312322
u = [15, 41, 57, 63]
elif M == 4 and Q == 16 and La == 1 and Lp == 4: # rate = 2, maxp = 0.256578
u = [31, 61, 49, 59]
elif M == 4 and Q == 32 and La == 1 and Lp == 2: # rate = 2, maxp = 0.312322
u = [51, 21, 5, 3]
elif M == 4 and Q == 16 and La == 1 and Lp == 8: # Rate = 2.25
u = [21, 37, 91, 83]
elif M == 4 and Q == 8 and La == 8 and Lp == 16: # rate = 3, maxp = 0.0260332
u = [114, 25, 14, 99]
elif M == 4 and Q == 16 and La == 4 and Lp == 16: # rate = 3, maxp = 0.0546157
u = [97, 145, 236, 25]
elif M == 4 and Q == 32 and La == 4 and Lp == 8: # rate = 3, maxp = 0.0557874
u = [196, 108, 252, 65]
elif M == 4 and Q == 64 and La == 1 and Lp == 16: # Rate = 3
u = [633, 603, 559, 797]
elif M == 8 and Q == 1 and La == 2 and Lp == 8: # rate = 0.875, maxp = 0.24203
u = [0, 0, 0, 0, 0, 0, 0, 0]
elif M == 8 and Q == 2 and La == 2 and Lp == 4: # rate = 0.875, maxp = 0.298721
u = [1, 1, 7, 2, 7, 6, 1, 7]
elif M == 8 and Q == 4 and La == 1 and Lp == 4: # rate = 0.875, maxp = 0.522137
u = [9, 11, 3, 7, 15, 13, 5, 1]
elif M == 8 and Q == 2 and La == 2 and Lp == 8: # rate = 1, maxp = 0.24203
u = [9, 1, 1, 15, 14, 1, 15, 10]
elif M == 8 and Q == 4 and La == 2 and Lp == 4: # rate = 1, maxp = 0.262553
u = [1, 11, 2, 11, 14, 5, 5, 15]
elif M == 8 and Q == 8 and La == 1 and Lp == 4: # rate = 1, maxp = 0.375254
u = [25, 31, 15, 13, 7, 1, 17, 3]
elif M == 16 and Q == 64 and La == 1 and Lp == 1: # rate = 0.625, maxp = 0
u = [63, 0, 18, 34, 62, 36, 37, 1, 26, 55, 37, 54, 46, 15, 39, 26]
else:
print("TASTCode.py does not support the given parameters M = %d, Q = %d, La = %d, and Lp = %d" % (
M, Q, La, Lp))
u = np.zeros(M)
return np.array(u)
