Improving the noise performance of energy detector based UWB systems by optimizing the receiver parameters

2009 9th International Symposium on Communications and Information Technology, ISCIT 2009, Icheon, 28-30 September 2009In an Ultra-WideBand (UWB) Low-Rate (LR) Wireless Personal Area Network (WPAN) application low-cost, low-power and low-complexity systems are expected to meet the requirements of the typical applications. These demands can only be satisfied by simple modulation schemes and easy to implement noncoherent receiver configurations. However performed field tests showed that the noise performance of such systems is quite poor. Therefore noise performance improvement is a must. This paper investigates and compares the Transmitted Reference (TR) modulation scheme with autocorrelation receiver, the On-Off Keying- (OOK) and the Pulse Position Modulation (PPM) schemes with energy detector for UWB impulse radio (IR) systems. The contribution provides an efficient method for the improvement of the noise performance of the UWB IR systems by matching the parameters of the receiver to the UWB pulse. Using this technique almost 8-dB noise performance improvement can be achieved. The Bit Error Rate (BER) of the three systems will be compared and an analytical expression will be provided for the estimation of the BER of each system.Department of Electronic and Information EngineeringRefereed conference pape

Performance improvement of autocorrelation detector used in UWB impulse radio

2010 IEEE International Symposium on Circuits and Systems: Nano-Bio Circuit Fabrics and Systems, ISCAS 2010, Paris, 30 May-2 June 2010Transmitted reference (TR) modulation scheme and the autocorrelation receiver offer a simple and robust transceiver configuration for ultra-wideband (UWB) communications. Unfortunately, the TR UWB system has a poor noise performance. The paper shows that the noise performance of a TR autocorrelation system can be improved considerably by placing a noise filter before the autocorrelation detector. The optimum frequency response of required noise filter is derived.Department of Electronic and Information EngineeringRefereed conference pape

Improving the coverage of ultra wideband impulse radio by pulse compression

2012 IEEE International Symposium on Circuits and Systems, ISCAS 2012, Seoul, 20-23 May 2012Radio coverage is limited by two parameters: (i) energy per bit radiated by the transmitter and (ii) BER performance of the receiver. In Ultra-Wideband Impulse Radio (UWB IR) the former is limited by the FCC Regulations while the latter depends on the detection algorithm. The fact that prevents the use of UWB IR devices in real applications is the unacceptable short radio coverage. The pulse compression technique, that simultaneously increases the maximum attainable energy per bit and introduces a processing gain at the receiver is proposed here to overcome this problem. As a result of pulse compression, the coverage of the new UWB chirp IR devices is 6-times longer than that of the conventional UWB IR devices, i.e., the radio coverage is extended from less than 10 meters up to 40 meters.Department of Electronic and Information EngineeringRefereed conference pape

From simulations to field tests: PXI-based software defined wireless platform for performance evaluation of FM-DCSK

2013 IEEE 56th International Midwest Symposium on Circuits and Systems, MWSCAS 2013, Columbus, OH, 4-7 August 2013A universal software defined wireless platform and a specific method for its application is proposed here to perform field test measurements for performance evaluation of communications system. The platform implements every application, starting from the transmitter and receiver of wireless link, the virtual measurement instruments for the baseband signals and the performance evaluation algorithm, purely in software which solution offers high level of flexibility, and it provides an easy and cheap solution for performance testing. Since a PXI-based HW platform is also included in the solution proposed here, every physical RF analog signals generated or processed in software can be recovered. Both the analog RF output and input of the transceiver are available, therefore real field tests can be performed, even more, the performance of a communications system can be evaluated in a real operating network. In this paper the performance of FM-DCSK wireless communications system, operated in the 2.4-GHz ISM band, is evaluated based on real field tests using PXI platform. A systematic method for validation of system implemented on the PXI HW is provided.Department of Electronic and Information EngineeringRefereed conference pape

Gated threshold compensated noncoherent PPM receiver for UWB impulse radio

2010 IEEE International Symposium on Circuits and Systems: Nano-Bio Circuit Fabrics and Systems, ISCAS 2010, Paris, 30 May-2 June 2010Since the coherent receivers are not feasible to implement low-cost ultra-wideband (UWB) impulse radio (IR) devices featuring extremely low power consumption, energy detector-based (ED-based) noncoherent receivers are more and more frequently chosen. The Pulse Polarity Modulation (PPM) scheme with a threshold compensated receiver is a promising candidate for the implementation of cheap and robust UWB IR devices. Unfortunately, the field tests and computer simulations have shown the well known fact that the noise performance of noncoherent demodulators is much behind that of their coherent counterparts. The poor noise performance results in a such a bad receiver sensitivity that prevents the use of noncoherent receivers in the majority of real applications. This contribution shows how the noise performance of non-coherent threshold compensated PPM receiver can be improved considerably by disabling the receiver outside of the UWB pulse where only channel noise and interference is observed. The novel receiver configuration, referred to as gated threshold compensated noncoherent PPM receiver offers an 8-dB improvement in receiver sensitivity.Department of Electronic and Information EngineeringRefereed conference pape