gr-gsm/python/trx/radio_if.py

132 lines
3.8 KiB
Python

#!/usr/bin/env python2
# -*- coding: utf-8 -*-
# GR-GSM based transceiver
# Follow graph implementation
#
# (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>
#
# All Rights Reserved
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
import pmt
import time
import grgsm
import osmosdr
from math import pi
from gnuradio import blocks
from gnuradio import gr
class radio_if(gr.top_block):
# PHY specific variables
shiftoff = 400e3
fc = 941.6e6 # TODO: set ARFCN to 0?
# Application state flags
trx_started = False
fc_set = False
def __init__(self, phy_args, phy_sample_rate,
phy_rx_gain, phy_tx_gain, phy_ppm,
phy_rx_antenna, phy_tx_antenna,
trx_remote_addr, trx_base_port):
print("[i] Init Radio interface")
# PHY specific variables
self.rx_gain = phy_rx_gain
self.tx_gain = phy_tx_gain
gr.top_block.__init__(self, "GR-GSM TRX")
shift_fc = self.fc - self.shiftoff
##################################################
# PHY Definition
##################################################
self.phy = osmosdr.source(args = "numchan=%d %s" % (1, phy_args))
self.phy.set_bandwidth(250e3 + abs(self.shiftoff), 0)
self.phy.set_center_freq(shift_fc, 0)
self.phy.set_sample_rate(phy_sample_rate)
self.phy.set_freq_corr(phy_ppm, 0)
self.phy.set_iq_balance_mode(2, 0)
self.phy.set_dc_offset_mode(2, 0)
self.phy.set_gain_mode(False, 0)
self.phy.set_gain(self.rx_gain, 0)
self.phy.set_if_gain(20, 0)
self.phy.set_bb_gain(20, 0)
self.phy.set_antenna(phy_rx_antenna, 0)
##################################################
# GR-GSM Magic
##################################################
self.blocks_rotator = blocks.rotator_cc(
-2 * pi * self.shiftoff / phy_sample_rate)
self.gsm_input = grgsm.gsm_input(
ppm = phy_ppm, osr = 4, fc = self.fc,
samp_rate_in = phy_sample_rate)
self.gsm_receiver = grgsm.receiver(4, ([0]), ([]))
self.gsm_clck_ctrl = grgsm.clock_offset_control(
shift_fc, phy_sample_rate, osr = 4)
self.gsm_ts_filter = grgsm.burst_timeslot_filter(0)
self.gsm_ts_filter.set_policy(grgsm.FILTER_POLICY_DROP_ALL)
self.gsm_trx_burst_if = grgsm.trx_burst_if(
trx_remote_addr, str(trx_base_port))
##################################################
# Connections
##################################################
self.connect((self.phy, 0), (self.blocks_rotator, 0))
self.connect((self.blocks_rotator, 0), (self.gsm_input, 0))
self.connect((self.gsm_input, 0), (self.gsm_receiver, 0))
self.msg_connect((self.gsm_receiver, 'measurements'),
(self.gsm_clck_ctrl, 'measurements'))
self.msg_connect((self.gsm_clck_ctrl, 'ctrl'),
(self.gsm_input, 'ctrl_in'))
self.msg_connect((self.gsm_receiver, 'C0'),
(self.gsm_ts_filter, 'in'))
self.msg_connect((self.gsm_ts_filter, 'out'),
(self.gsm_trx_burst_if, 'bursts'))
def check_available(self):
return self.fc_set
def shutdown(self):
print("[i] Shutdown Radio interface")
self.stop()
self.wait()
def set_fc(self, fc):
self.phy.set_center_freq(fc - self.shiftoff, 0)
self.gsm_input.set_fc(fc)
self.fc_set = True
self.fc = fc
def set_gain(self, gain):
self.phy.set_gain(gain, 0)
self.gain = gain