0.34-THz Wireless Link Based on High-Order Modulation for Future Wireless Local Area Network Applications

This paper presents a 0.34-THz wireless link for future wireless local area networks (WLANs), which is based on high order 16-quadrature amplitude modulation (16QAM). The system adopts super heterodyne transceivers and parallel digital signal-processing techniques. The 0.34-THz transceiver consists of a 0.34-THz subharmonic mixer, a 0.34-THz waveguide H-ladder bandpass filter, and a 0.17-THz multiplier chain. Two 0.34-THz Cassegrain antennas with 48.4-dBi gain have been developed to extend the transmission distance. Based on a 32-way parallel signal processing, we have successfully realized the 3-Gb/s, 16QAM real-time modulator and demodulator. The measured data indicate that the lowest bit error rate of the 0.34-THz, 3-Gb/s data link is <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${\hbox{1.784}}\times {\hbox{10}}^{-10}$</tex></formula> over a 50.0-m line-of-sight channel. The maximum received energy per bit to noise power spectral density ratio ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\hbox{E}}_{\rm b}/{\hbox{N}}_{0}$</tex></formula> ) is 23.8 dB, while the output power of transmitter is <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$-$</tex> </formula> 17.5 dBm and the noise temperature of receiver is 5227 K. In addition, this paper presents a 0.34-THz WLAN prototype based on IEEE 802.11b/g protocol. The WLAN prototype, which consists of an access point and two terminal nodes, achieves a transmission data rate of 6.536 Mb/s over 1.15 m by using rectangular horn antennas.