18 / 2016-06-26 19:41:36

Development of LTE-CommSense Infrastructure using SDR Platform

lte,sdr ,commsense,usrp,dl,ue,mib,sib1

Communication infrastructure based environment
monitoring, named LTE-CommSense by the authors, can be used
in many environment sensing tasks e.g. crop growth monitoring,
disaster monitoring, sea state monitoring, snow avalanche moni-
toring, security of large unmanned landscapes etc. In CommSense
we use the channel state information (CSI) to get an estimate
of change in the channel properties [1]–[3]. After the channel
information is received, this is utilized to obtain phenomeno-
logical knowledge of the environment using ASIN (Application
Specific INstrumentation) framework. As Long Term Evolution
(LTE) will have wide coverage in the near future, it is the most
suitable option for the communciation environment. This paper
describes the initial work of implementing the LTE-CommSense
infrastructure in a software defined radio (SDR) platform to
capture live LTE downlink (DL) signal from LTE base stations
to the user equipment (UE). Universal Software Radio Peripheral
(USRP) N200 SDR platform is used for this purpose. USRP
N200 is modelled as an UE and captures the downlink data.
After correcting the timing offset and frequency offset values
of the received signal, we decode the Master Information Block
(MIB) and System Information Block 1 (SIB1) and finally form
channel estimation and equalization to extract the channel CSI
information. This CSI information changes if there is a change in
the environment. We captured live LTE DL signal in two different
environment situations. Then corresponding CSI information
estimated and plotted in a cluster diagram. We observed that the
data corresponding to two different environmets are generating
two seperate clusters which establishes that the proposed system
is feasible in practice. This CSI information will be used in
ASIN framework to obtain phenomenological knowledge of the
environment.