Wajih Abu-Al-Saud

Efficient wideband channelizer for software radio systems using modulated PR filterbanks

An efficient method is proposed for channelizing frequency division multiplexed (FDM) channels in wideband software radio (SWR) received signals that do not satisfy the conditions required for polyphase decomposition of the discrete filterbank (DFB) channelizer. The proposed method, which uses modulated perfect reconstruction (PR) filterbanks, requires fewer computations than DFBs for channelizing wideband signals that are composed of FDM channels of nonequal bandwidths, especially when a large number of channels are extracted. The proposed channelizer, if applied in the reverse direction, can be used to synthesize a set of channels with nonequal bandwidths into a single wideband signal in SWR transmitters. A method is also proposed for efficiently designing the modulated PR filterbanks, which have a large number of subchannels and prototype filters with high stopband attenuations that are used in the proposed channelizer. The computational complexity of the proposed channelizer is compared with the complexity of the DFB channelizer for channelizing the wideband and high-dynamic-range signals that are typical of SWR systems, and simulation results of the proposed channelization method are discussed.

Modified CIC filter for sample rate conversion in software radio systems

Cascaded-integrator-comb (CIC) filters perform sample rate conversion (SRC) efficiently using only additions/subtractions. However, the limited number of tuning parameters may make conventional CIC filters unsuitable for SRC in software radio (SWR) systems. A simple modification to the CIC filter that enhances its SRC performance at the expense of requiring a few extra computations per output sample is proposed. Simulation results show that the modified CIC filter outperforms the conventional CIC filter for the purpose of SRC in SWR systems.

Efficient sample rate conversion for software radio systems

A new sample rate conversion (SRC) method for software radio (SWR) systems is proposed. The method, which uses the window filter design and Lagrange functions, requires fewer computations than other SRC methods over a range of SRC factors for the wideband and high dynamic range signals that are typical of SWR systems. The computational requirements of the proposed SRC method and other SRC methods are compared and simulation results of the proposed method are discussed.

Directive Stacked Patch Antenna for UWB Applications

Directional ultrawideband (UWB) antennas are popular in wireless signal-tracking and body-area networks. This paper presents a stacked microstrip antenna with an ultrawide impedance bandwidth of 114%, implemented by introducing defects on the radiating patches and the ground plane. The compact ( mm) antenna exhibits a directive radiation patterns for all frequencies of the 3–10.6 GHz band. The optimized reflection response and the radiation pattern are experimentally verified. The designed UWB antenna is used to maximize the received power of a software-defined radio (SDR) platform. For an ultrawideband impulse radio system, this class of antennas is essential to improve the performance of the communication channels.

Practical vs. Simulated Results of ISA100 Physical Layer

ISA100.11a is developed by International Society of Automation specially designed for Industrial wireless sensor networks. The main features of this standard are low power consumption, real time fast data transfer, scalability, security, reliability, co-existence with other network architectures and robustness in harsh industrial environment.ISA100 uses many layers for security and integrity of the system. This standard uses IEEE 802.15.4 standard in its physical layer which operates on 2.4 Ghz band and can support data rate of up to 250kbps. This paper compares experimental values with the simulated results on physical layer. Experimental results are conducted in Shedgum GOSP -3 Plant, Saudi Arabia. The simulated results are obtained from matlab using the same configurations and compared with each other. This paper takes into account received signal strength (RSSI) and packet error rate (PER).

Simulation of Industrial Wireless Sensor Network (IWSN) protocols.

Industrial Wireless Sensor Networks (IWSN) are preferred over bulky wired networks in industrial monitoring and automation. These sensors are used to access locations, which are technically unreachable. The use of IWSN not only reduced the cost of automation systems but also played a significant role in alarm management by real time data transfer. ZigBee and WirelessHART are already deployed protocols for IWSN. ISA100.11a developed by International Society of Automation was specially designed for IWSN. The main features of this standard are low power consumption, real time fast data transfer, scalability, security, reliability, coexistence with other network architectures and robustness in harsh industrial environments. To achieve these features, these protocols use layer structure, which provides security, fast and reliable data transfer. IEEE 802.15.4 is used at its physical layer with variable data slots. This paper presents the results of the simulation of ZigBee, WirelessHART and ISA100 done on Pymote framework, which is extended by one of the authors, and Castalia. This paper compares and discusses the simulated results obtained from all three protocols.

On Industrial Wireless Sensor Network (IWSN) and Its Simulation Using Castalia

Wireless automation is an emerging field of research that aims at significant savings in installation time and costs of cabling in automation systems, while providing a new level of flexibility for system design, reconfiguration, and agility. Wireless sensor networks (WSNs) are a rather new technology, with its origins tracing back to the early 1980s through the Distributed Sensor Networks (DSNs) program at the Defense Advanced Research Project Agency (DARPA) of the US Department of Defense. Industrial Wireless Sensor Network (IWSN) evolved from WSN and are specially designed, keeping in mind the demands and nature of industry. Two common protocols ZigBee and WirelessHART were designed for general commercial use and later adopted for industrial applications. ISA100.11a developed by International Society of Automation, was specially designed for IWSN. These protocols use layer structure which allow secure, fast and reliable data transfer. IEEE 802.15.4 is used at its physical layer with variable data slots. This paper presents the results of the simulation of ZigBee, WirelessHART and ISA100 protocols done using Castalia. This paper compares and discusses the simulated results obtained from all three protocols.

Characterization of Reconfigurable MIMO Antennas for Channel Capacity in an Indoor Environment

In this paper, three different frequency reconfigurable multiple-input-multiple output (MIMO) antennas are characterized in terms of their channel capacity performance in an indoor environment. Two 2 × 2 and one 4 × 4 MIMO antenna configurations are investigated. A complete MIMO system is implemented using software defined radio (SDR) platform. The antenna under test can be used at either transmitter or receiver ends. The channel capacity of the system is evaluated by computing the channel coefficient matrix. The measurements are performed at 2.45 GHz for line of sight (LOS) and non-line of sight (NLOS) scenarios. A comparison of the antennas is performed with an ideal system scenario with totally uncorrelated channels as well as an array of standard monopoles which are half-wavelength apart. The effects of antenna element efficiencies, radiation patterns and spacings on the channel capacity are discussed.

A low complexity direction finding system based on a six-port integrated MIMO antenna system

In this paper, a low complexity microwave based direction finding (DF) system is presented. The proposed system consists of single six-port (SP) circuit integrated with a reconfigurable multiple-input-multiple-output (MIMO) antenna system. The proposed design is a complete integrated solution with DF capabilities for cognitive radio platforms. The design is suitable to be used in compact wireless handheld and mobile communication devices. The SP circuit covers a wide frequency band (1.68∼2.25 GHz) while the reconfigurable MIMO antenna system cover several frequency bands between 0.7 GHz to 3 GHz. The fabricated integrated system achieves ±16° accuracy in its direction of arrival estimates.