Hi all,
I am trying to use cc1k of ucla_zigbee_phy. The testbench are
cc1k_txtest.py and cc1k_rxtest.py in which the signal source and sink
are amended to UHD since my platform is USRP E100. There is nothing
outputs from the RX TB. I checked the ucla_sos_packet_sink.cc, it can
receive data when TX sends although there is no data matches the access
code. I want to know why there is no access code be demodulated
correctly so I studied the relevant codes of cc1k.py and
cc1k_sos_pkt.py. Many problems emerge in front of me. I don’t know if
anybody has succeeded in using it. If so, very thankful for your explain
and suggestions.
1 The spb in TX and sps in RX are set to 8, what is the reason?
2 In TX there is preamble but in ucla_sos_packet_sink.cc, no preamble
needs to be found before the sync data. Actually it is just a simple
comparison between input data and the access code. So why we need
transmit preamble in TX?
3 In cc1k_txtest.py the access code is set as 0x33 plus 0xcc, but in
cc1k_sos_pkt the access code of cc1k_demod_pkts module is
0x999999995a5aa5a5. The ucla_sos_packet_sink.cc also requires the access
code to be 8 bytes. How can the access code in TX be discerned in RX?
BTW, even after I changed the access code of TX to 0x999999995a5aa5a5,
the packet_sink still can not detect out the sync data.
4 In cc1k.py, the cc1k_mod module sets ‘sensitivity’ to 3.5*pi / spb but
the cc1k_demod module set ‘sensitivity’ to (pi/2)/sps. Actually I am not
sure what is the functionality of this variable but I think it may
should be set as identical in both mod and demod module.
5 In cc1k_demod module, the alpha variable, which is parameter of
gr.single_pole_iir_filter_ff, is set to 0.0512/sps. I don’t know why it
should be this value. In ieee802_15_4.py, the demodulation module sets
it to 0.0008/self.sps. What is foundation to set this variable?
At last, what configuration in TX and RX can make the communication runs
well?
Appreciate in advance for your reply.
Sincerely,
Zhonghua