4 research outputs found
Design Of Transceiver For UWB Applications
An RF front-end Direct Conversion (DICON) transceiver architecture for Mode 1
multiband Orthogonal Frequency Division Multiplexing (OFDM) applications is
presented in this dissertation. This effort on building a prototype is to serve as a
reference model for workability to be transferred onto a single chip system using The RF front-end transceiver is designed on system level
using Agilent’s Advanced Design System (ADS) and the prototype was built on the
FR4 type printed circuit board (PCB) employing passive networks such as power-splitter, low-pass and band-pass filters as well as quadrature phase shifters, for better
integration with other devices on PCB. The major operations blocks such as the I&Q
Modulator, I&Q Demodulator and the Voltage Controlled Oscillator (VCO) employed
are microwave-based components from Mini-Circuits while the Low-Noise Amplifier
(LNA) and Power Amplifier (PA) employed are p-type High Electron Mobility
Trasnsistor (pHEMT) based, from Agilent Technologies. The transceiver prototype is
complete with microstrip rectangular patch antennas which have a bandwidth of
17MHz and a 3dB beamwidth of 80° for wireless transmission. The band-pass filter
and the low-pass filter have been designed with third order response possessing a
bandwidth of 423MHz and 260MHz respectively. The transceiver system has an
operational bandwidth of up to 200MHz but its bandwidth is severely limited by the
rectangular patch antenna, thus allowing only a 17MHz operational bandwidth. Since
high-frequency devices are not commercially available, the operational frequency of
the transceiver system has to be scaled down to a carrier frequency (LO) of 1.60GHz
from the intended 3.96GHz. Also, the test baseband signal has been set to 80MHz to
accommodate bandwidth restrictions of the overall system. The prototype was tested
separately as a transmitter and a receiver to ease the testing and troubleshooting
procedure. The prototype was tested to have a stability of operation of up to 2.5m.
The average transmit power is -36dBm without utilizing a PA while the receiver
sensitivity is around -65dBm. The recovered baseband signal consists of the I and Q
signals which were found to be at the frequency test baseband signal of 80MHz, with
a maximum power of -22dBm. The I and Q signal exhibit a 20% mismatch in
amplitude but otherwise is at quadrature phase apart
MIMO OFDM Radar-Communication System with Mutual Interference Cancellation
This work describes the OFDM-based MIMO Radar-Communication System, intended for operation in a multiple-user network, especially the automotive sector in the vehicle-to vehicle/infrastructure network. The OFDM signals however are weak towards frequency offsets causing subcarrier misalignment and corrupts the radar estimation and the demodulation of the communication signal. A simple yet effective interference cancellation algorithm is detailed here with real time measurement verification
MIMO OFDM Radar-Communication System with Mutual Interference Cancellation
This work describes the OFDM-based MIMO Radar-Communication System, intended for operation in a multiple-user network, especially the automotive sector in the vehicle-to vehicle/infrastructure network. The OFDM signals however are weak towards frequency offsets causing subcarrier misalignment and corrupts the radar estimation and the demodulation of the communication signal. A simple yet effective interference cancellation algorithm is detailed here with real time measurement verification