Data Transmission with Terahertz Communication Systems
125
account: propagation channel models, interference with other applications such as
radio astronomy and enabling technologies.
An effective implementation of THz technology needs the understanding of broadcast channel characteristics. However, because the THz communication systems have
several attenuations and high diffraction losses, establishing radio links in the presence of shadowing conditions need beamforming to benefit from the scattering and
reflection processes. To get hold of practical channel models for wireless channels
in upcoming indoor THz technology, it is essential to understand the behavior of
the wireless channel. Therefore, to design any channel model for the THz communication system, careful considerations should be given to the multi-path effects. In
addition, it is needed to be acquainted with the knowledge of broadcast channels
such as attenuation caused by building according to its material properties. The THz
channel has been characterized experimentally at distances of less than 1 m, and it is
compared with some model used frequencies, 290 and 310 GHz [18]. In [19], measurements have been done to determine the effect of materials properties of classic
house materials on channel behavior. In order to determine the reflection coefficients,
Fresnel’s equations are used and demonstrated that the material reflectivity must be
calculated to model the wireless channel for the upcoming generation THz technology together with NLOS scenarios. For example, in [20], a true interference scenario
is analyzed. Recently, measurement of channel properties has been done for THz
technology and compared with the simulation results obtained based on ray-tracing
methods at 300 GHz [21].
4 Modulation Schemes
Single carrier modulations have been extensively used in cellular systems such as
GSM, CDMA2000, and UMTS WCDMA. Thanks to their time domain symbol
sequencing; they typically provide low PAPR. Improving the power efficiency of HPA
and battery life can be extended. This makes a single carrier waveform particularly
suited for use cases such as WiMAX and UMTS where battery power and coverage
extension are the main optimization goals.
On the other hand, single carrier waveforms suffer link degradation under frequency selective channels and typically require the use of equalizer to obtain high
spectral efficiency under the multi-path effect.
4.1 OOK Modulation
OOK modulation is a very popular modulation used in wireless system. This technique is used largely. Thanks to its simplicity, the needed limited bandwidth, and low
implementation costs. OOK modulation has the advantage of allowing the modulator to be lazy when transmitting “zero.” Therefore, it has low power consumption.
125
account: propagation channel models, interference with other applications such as
radio astronomy and enabling technologies.
An effective implementation of THz technology needs the understanding of broadcast channel characteristics. However, because the THz communication systems have
several attenuations and high diffraction losses, establishing radio links in the presence of shadowing conditions need beamforming to benefit from the scattering and
reflection processes. To get hold of practical channel models for wireless channels
in upcoming indoor THz technology, it is essential to understand the behavior of
the wireless channel. Therefore, to design any channel model for the THz communication system, careful considerations should be given to the multi-path effects. In
addition, it is needed to be acquainted with the knowledge of broadcast channels
such as attenuation caused by building according to its material properties. The THz
channel has been characterized experimentally at distances of less than 1 m, and it is
compared with some model used frequencies, 290 and 310 GHz [18]. In [19], measurements have been done to determine the effect of materials properties of classic
house materials on channel behavior. In order to determine the reflection coefficients,
Fresnel’s equations are used and demonstrated that the material reflectivity must be
calculated to model the wireless channel for the upcoming generation THz technology together with NLOS scenarios. For example, in [20], a true interference scenario
is analyzed. Recently, measurement of channel properties has been done for THz
technology and compared with the simulation results obtained based on ray-tracing
methods at 300 GHz [21].
4 Modulation Schemes
Single carrier modulations have been extensively used in cellular systems such as
GSM, CDMA2000, and UMTS WCDMA. Thanks to their time domain symbol
sequencing; they typically provide low PAPR. Improving the power efficiency of HPA
and battery life can be extended. This makes a single carrier waveform particularly
suited for use cases such as WiMAX and UMTS where battery power and coverage
extension are the main optimization goals.
On the other hand, single carrier waveforms suffer link degradation under frequency selective channels and typically require the use of equalizer to obtain high
spectral efficiency under the multi-path effect.
4.1 OOK Modulation
OOK modulation is a very popular modulation used in wireless system. This technique is used largely. Thanks to its simplicity, the needed limited bandwidth, and low
implementation costs. OOK modulation has the advantage of allowing the modulator to be lazy when transmitting “zero.” Therefore, it has low power consumption.