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Abstract
Time modulation provides a simple way to control the power radiation pattern of an antenna array. By appropriately selecting the parameters of a Time-Modulated Array (TMA) it is possible to obtain a reconfigurable pencil beam adequate for wireless communications. This work focuses on the impact of a TMA on the Bit Error Ratio (BER) performance of a wireless communication receiver with a linear digital modulation. We show how the BER of such a receiver is affected by the TMA synthesis variables.
Notes
No potential conflict of interest was reported by the authors.
1 It can be seen from that figure that the main axes of the antennas are considered to be both parallel to the -axis of a global coordinate system.
2 In this case, as the array elements are isotropic, the polarization matching factor is tacitly regarded as unity.
3 The minimum error probability () criterion [Citation9] is applied in Detection Theory when a multiple hypothesis test
is present (
True, False
being True if
was sent and False otherwise), with
for an
-ary scheme. In addition, both a priory probabilities
and probability density functions
are assumed to be known for the indices
. The detector chooses the
that maximizes
which is equivalent to minimize
, where
is the Kronecker delta.
4 In fact, it corresponds to a simplified version of the distribution given in [Citation10], where the very small (close to 0) and very large (close to 1) are replaced by 0 and 1, respectively. Such a simplification, which further reduces the first harmonic level and does not change the SLL significantly, is done also in view of the fact that very small or very large time durations would lead to technical problems (too fast switches).
