Change in ...osmocom-bb[master]: trx_toolkit/gsm_shared.py: introduce a new enum TrainingSeqGMSK

fixeria gerrit-no-reply at lists.osmocom.org
Mon Jul 8 03:42:55 UTC 2019


fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmocom-bb/+/14690


Change subject: trx_toolkit/gsm_shared.py: introduce a new enum TrainingSeqGMSK
......................................................................

trx_toolkit/gsm_shared.py: introduce a new enum TrainingSeqGMSK

Training Sequences are defined in 3GPP TS 45.002, and used by the
transceiver for detecting bursts. This change introduces an enum
with training sequences for GMSK for Access and Normal bursts.

This enumeration is needed for the follow-up changes that implement
TRXD header version 1 support, and can now be used by RandBurstGen.

Change-Id: If3bf102019ef53d6ee9ad230ef98bb45845b5af5
---
M src/target/trx_toolkit/gsm_shared.py
1 file changed, 78 insertions(+), 1 deletion(-)



  git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/90/14690/1

diff --git a/src/target/trx_toolkit/gsm_shared.py b/src/target/trx_toolkit/gsm_shared.py
index d2f8278..d76978e 100644
--- a/src/target/trx_toolkit/gsm_shared.py
+++ b/src/target/trx_toolkit/gsm_shared.py
@@ -4,7 +4,7 @@
 # TRX Toolkit
 # Common GSM constants
 #
-# (C) 2018 by Vadim Yanitskiy <axilirator at gmail.com>
+# (C) 2018-2019 by Vadim Yanitskiy <axilirator at gmail.com>
 #
 # All Rights Reserved
 #
@@ -22,6 +22,8 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+from enum import Enum
+
 # TDMA definitions
 GSM_SUPERFRAME = 26 * 51
 GSM_HYPERFRAME = 2048 * GSM_SUPERFRAME
@@ -29,3 +31,78 @@
 # Burst length
 GSM_BURST_LEN = 148
 EDGE_BURST_LEN = GSM_BURST_LEN * 3
+
+class BurstType(Enum):
+	""" Burst types defined in 3GPP TS 45.002 """
+	DUMMY	= ("DB") # Dummy burst (5.2.6)
+	SYNC	= ("SB") # Synchronization Burst (5.2.5)
+	FREQ	= ("FB") # Frequency correction Burst (5.2.4)
+	ACCESS	= ("AB") # Access Burst (5.2.7)
+	NORMAL	= ("NB") # Normal Burst (5.2.3)
+	# HSR	= ("HB") # Higher symbol rate burst (5.2.3a)
+
+class TrainingSeqGMSK(Enum):
+	""" Training Sequences defined in 3GPP TS 45.002 """
+
+	# Training Sequences for Access Burst (table 5.2.7-3)
+	AB_TS0 = (0, BurstType.ACCESS, "01001011011111111001100110101010001111000")
+	AB_TS1 = (1, BurstType.ACCESS, "01010100111110001000011000101111001001101")
+	AB_TS2 = (2, BurstType.ACCESS, "11101111001001110101011000001101101110111")
+	AB_TS4 = (4, BurstType.ACCESS, "11001001110001001110000000001101010110010")
+
+	# Training Sequences for Access Burst (table 5.2.7-4)
+	AB_TS3 = (3, BurstType.ACCESS, "10001000111010111011010000010000101100010")
+	AB_TS5 = (5, BurstType.ACCESS, "01010000111111110101110101101100110010100")
+	AB_TS6 = (6, BurstType.ACCESS, "01011110011101011110110100010011000010111")
+	AB_TS7 = (7, BurstType.ACCESS, "01000010110000011101001010111011100010000")
+
+	# Training Sequences for Synchronization Burst (table 5.2.5-3)
+	SB_TS0 = (0, BurstType.SYNC, "1011100101100010000001000000111100101101010001010111011000011011")
+	SB_TS1 = (1, BurstType.SYNC, "1110111001101011001010000011111011110100011111101100101100010101")
+	SB_TS2 = (2, BurstType.SYNC, "1110110000110111010100010101101001111000000100000010001101001110")
+	SB_TS3 = (3, BurstType.SYNC, "1011101000111101110101101111010010001011010000001000111010011000")
+
+	# Training Sequences for Normal Burst (table 5.2.3a, TSC set 1)
+	NB_TS0 = (0, BurstType.NORMAL, "00100101110000100010010111")
+	NB_TS1 = (1, BurstType.NORMAL, "00101101110111100010110111")
+	NB_TS2 = (2, BurstType.NORMAL, "01000011101110100100001110")
+	NB_TS3 = (3, BurstType.NORMAL, "01000111101101000100011110")
+	NB_TS4 = (4, BurstType.NORMAL, "00011010111001000001101011")
+	NB_TS5 = (5, BurstType.NORMAL, "01001110101100000100111010")
+	NB_TS6 = (6, BurstType.NORMAL, "10100111110110001010011111")
+	NB_TS7 = (7, BurstType.NORMAL, "11101111000100101110111100")
+
+	# TODO: more TSC sets from tables 5.2.3b-d
+
+	def __init__(self, tsc, bt, seq_str, tsc_set = 0):
+		# Training Sequence Code
+		self.tsc = tsc
+		# Burst type
+		self.bt = bt
+
+		# Training Sequence Code set
+		# NOTE: unlike the specs. we count from zero
+		self.tsc_set = tsc_set
+
+		# Generate Training Sequence bits
+		self.seq = [int(x) for x in seq_str]
+
+	@classmethod
+	def pick(self, burst):
+		# Normal burst TS (26 bits)
+		nb_seq = burst[3 + 57 + 1:][:26]
+		# Access burst TS (41 bits)
+		ab_seq = burst[8:][:41]
+		# Sync Burst TS (64 bits)
+		sb_seq = burst[3 + 39:][:64]
+
+		for ts in list(self):
+			# Ugly Python way of writing 'switch' statement
+			if ts.bt is BurstType.NORMAL and ts.seq == nb_seq:
+				return ts
+			elif ts.bt is BurstType.ACCESS and ts.seq == ab_seq:
+				return ts
+			elif ts.bt is BurstType.SYNC and ts.seq == sb_seq:
+				return ts
+
+		return None

-- 
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Gerrit-Project: osmocom-bb
Gerrit-Branch: master
Gerrit-Change-Id: If3bf102019ef53d6ee9ad230ef98bb45845b5af5
Gerrit-Change-Number: 14690
Gerrit-PatchSet: 1
Gerrit-Owner: fixeria <axilirator at gmail.com>
Gerrit-MessageType: newchange
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