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M. El Ghzaoui and S. Das
2 Choice of the Carrier Frequency
The THz requires accurate modeling of the channel before implementing the THz
communication system. Implementing a system at a high carrier frequency allows one
to achieve a higher bandwidth which consequently provides a high data rate wireless
communications system at the expense of a reduced range. Within ten years, the
promised capacity for the wireless system will allow customers to be able to access
individual wavelengths at up to 100 Gbit/s. On the other side, academics have recently
been searching using high-frequency radio waves more than 100 GHz to allow high
data rate wireless communication system. The THz communications system would
adopt a high data rate of about 100 Gbit/s using modulation techniques such as QAM
thanks to their ultra-broad bandwidth [7–10].
For frequencies more than 100 GHz, elementary functional components like a
mixer, frequency multiplier [11], electronic oscillator such as voltage-controlled
oscillator [12] and electronic circuit like phase-locked loop, [13] and conventional
radio transmitters and receivers circuits [14, 15] for wireless system, such as remote
sensing (such as radar) and data communications, have been verified. The 120-GHz
band has been developed to be used for wireless system. Thanks to the progress of
the semiconductor electronics industry especially with respect to data rate, stability,
distance, and cost [14]. Japan has officially modified the radio regulations, including
new spectrum allocations (116 to 134 to 120 GHz band) to the wireless system for the
data share. Japanese allocation was the first one of radio system using frequency more
than 100 GHz. The data rate of the wireless channels has been progressed to 20 Gbit/s
using QPSK as transmission technique [15]. Working at 240 GHz, carrier frequency
corresponds to an on-chip wavelength of about 360 µm. Additionally, for long-range
wireless communication link using transmitter lenses, the atmospheric attenuation
in wireless systems in this band is low. Operating at 250 GHz corresponds to low
cut off frequency with a maximum oscillation frequency fmax of 200 GHz in 65 nm
bulk CMOS technology. In [16], an ASK receiver MMIC is integrated with an onchip dipole antenna and RF module to operate at 300 GHz for THz communication
for data transmission upto 24 Gbps over 0.3 m. For the next-generation wireless
networks with high data rates, in particular, the band between 275 and 3000 GHz
has not been allocated for particular usages until now. On the receiver side, a high
voltage diode in the form of Schottky barrier is used for demodulation due to its high
cutoff frequency.
3 Channel Modeling
The capacity of 100 Gbit/s would be probable in the next-generation wireless system.
Many efforts have been taken to standardize the spectral efficiency; one of them
has been introduced in [17] by Kürner et al. To model the channel, they take into
M. El Ghzaoui and S. Das
2 Choice of the Carrier Frequency
The THz requires accurate modeling of the channel before implementing the THz
communication system. Implementing a system at a high carrier frequency allows one
to achieve a higher bandwidth which consequently provides a high data rate wireless
communications system at the expense of a reduced range. Within ten years, the
promised capacity for the wireless system will allow customers to be able to access
individual wavelengths at up to 100 Gbit/s. On the other side, academics have recently
been searching using high-frequency radio waves more than 100 GHz to allow high
data rate wireless communication system. The THz communications system would
adopt a high data rate of about 100 Gbit/s using modulation techniques such as QAM
thanks to their ultra-broad bandwidth [7–10].
For frequencies more than 100 GHz, elementary functional components like a
mixer, frequency multiplier [11], electronic oscillator such as voltage-controlled
oscillator [12] and electronic circuit like phase-locked loop, [13] and conventional
radio transmitters and receivers circuits [14, 15] for wireless system, such as remote
sensing (such as radar) and data communications, have been verified. The 120-GHz
band has been developed to be used for wireless system. Thanks to the progress of
the semiconductor electronics industry especially with respect to data rate, stability,
distance, and cost [14]. Japan has officially modified the radio regulations, including
new spectrum allocations (116 to 134 to 120 GHz band) to the wireless system for the
data share. Japanese allocation was the first one of radio system using frequency more
than 100 GHz. The data rate of the wireless channels has been progressed to 20 Gbit/s
using QPSK as transmission technique [15]. Working at 240 GHz, carrier frequency
corresponds to an on-chip wavelength of about 360 µm. Additionally, for long-range
wireless communication link using transmitter lenses, the atmospheric attenuation
in wireless systems in this band is low. Operating at 250 GHz corresponds to low
cut off frequency with a maximum oscillation frequency fmax of 200 GHz in 65 nm
bulk CMOS technology. In [16], an ASK receiver MMIC is integrated with an onchip dipole antenna and RF module to operate at 300 GHz for THz communication
for data transmission upto 24 Gbps over 0.3 m. For the next-generation wireless
networks with high data rates, in particular, the band between 275 and 3000 GHz
has not been allocated for particular usages until now. On the receiver side, a high
voltage diode in the form of Schottky barrier is used for demodulation due to its high
cutoff frequency.
3 Channel Modeling
The capacity of 100 Gbit/s would be probable in the next-generation wireless system.
Many efforts have been taken to standardize the spectral efficiency; one of them
has been introduced in [17] by Kürner et al. To model the channel, they take into