3C Tecnología. Glosas de innovación aplicadas a la pyme. ISSN: 2254 – 4143 Ed. 35 Vol. 9 N.º 3 Septiembre - Diciembre
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https://doi.org/10.17993/3ctecno/2020.v9n3e35.59-75
1. INTRODUCTION
Wireless Sensor Networks (WSNs) are the combination of many tiny sensing elements for transferring
data from source to destination using multi-hop transmission. There are a number of applications in
which real time monitoring is required so a huge amount of data is collected after the collection of this
data various mathematical transformations are required to convert this raw data into useful information.
Some applications require security of the data whereas for some applications such as wireless multimedia
sensor network major concern is accuracy of the data and high data transfer rate. In agriculture, these
networks can provide the report about the growth rate of plants. This can reduce labor work and the
cost of production by Zhen, Hong, and Wang (2011) and Sun et al. (2011). However, sensor network has
tiny nodes with limited transmission capability and limited battery lifetime so long distance transmission
of data is also a challenging task in WSNs. According to an Article “Wireless Channel Propagation
Characteristics and modeling research in Rice eld sensor networks” by Gao et al. (2018), in wireless
sensor network the quality of communication depends upon the condition of the environment where the
sensor network is planned to operate for example the attenuation speed in wireless channel propagation is
directly related to the development of the rice plant. In this paper author observed that crop plants suer
from dierent wireless channels eects such as reection, scattering and diraction, So various diversity
techniques helps us to mitigate these eects in sensor networks. Farhang-Boroujeny and Moradi (2016)
showed that, Orthogonal Frequency Division Multiplexing (OFDM) modulation technique played an
important role in wireless communication systems due to its ability of high frequency selectivity and
achieving high data transfer rate without any Inter Symbol Interference (ISI).
When data travel a long distance then several multipath eects like fading and reection of signals are also
coming into consideration. Diversity techniques are also playing an important role in any communication
because these techniques mitigate the eect of multipath fading and shadowing from buildings and objects
(Alamouti, 1998). According to a special issue on codes and graphs, in the applications where secure
communication is required, the spread spectrum system plays an important role, for the applications