Telecommunications are part of people’s daily lives. Also, nowadays, a complete
"technological illiteracy" is hard to be found in the so-called developed countries. To the point
of being almost a necessity in everyday life, telecommunications must evolve to meet this need.
One of the most widely used transmission techniques in mobile communications today
is Orthogonal Frequency-Division Multiplexing (OFDM). Adopted in the fourth generation of
mobile communications (4G), much for its ability to deal with frequency-selective channels and
good spectral efficiency, it is one of the candidate schemes to be in the fifth generation of
mobile communications (5G). Despite the advantages, OFDM signals have high envelope
fluctuations, making them sensitive to nonlinear effects. Several techniques were proposed to
reduce these fluctuations, however they required nonlinear operations that worsened the
performance of receivers. Nevertheless, it has recently been shown that the distortion effects
caused by nonlinearity is no longer seen as a problem, but as information. In fact, with this
discovery, it becomes possible to employ optimal receivers in order to improve the
performance. Despite that, these receivers have a very high complexity and, to try to solve this
problem, sub-optimal receivers have been proposed.
The sub-optimal receiver presented in this thesis is based on an optimization algorithm
called Fireworks Algorithm (FWA). The thesis includes: a study of the parameters of the
algorithm in order to understand its true impact on Bit Error Rate (BER) performance; a
comparison of the BER for different channels: Additive White Gaussian Noise (AWGN) and
Frequency-Selective; and a proposal for an FWA variant that tries to reduce the receiver’s
complexity even more
