Citation Context

...ION There are a number of ways to implement our multi-variable optimization scheme. We use USRP2 (Universal Software Radio Peripheral) as our hardware device and choose a co-operative relaying scheme =-=[41]-=- on our node-setup. The channel that the implementation will use is the air, the signal is transmitted and received using USRP2 antennae. The room of the laboratory where the USRPs are placed will pro...

Citation Context

...ch can be protected. A mobile node’s position is hard to mimic and hence when two nodes interact in a password protected environment, mobile nodes have far better security than the normal static ones =-=[6]-=-. The other advantages of mobile nodes include the amount of energy that can be conserved in various scenarios. When the nodes appear to be stationary, it is easier to conserve the energy by optimal u...

Citation Context

...ocation in communication networks has been dealt with using a variety of approaches. The first approach dealing with Network Utility Maximization has been given by Kelly et al. in their seminal paper =-=[3]-=-. The NUM framework deals with the problem of optimal network resource allocation and solves it using a set of differential equations. That paper produced results for elastic type of traffic that desc...

Citation Context

...ios. When the nodes appear to be stationary, it is easier to conserve the energy by optimal usage. However, a proper routing scheme has potential to conserving energy also in the case of mobile nodes =-=[5]-=- . The mobile WSNs should have a highly cooperative communication channel in terms of independence and also sharing network protocols. The mobile sensor networks require that hierarchy be established ...

Citation Context

... use of this fact to generate the error signal. Hence this block fixes the clock mismatches between the transmitter and receiver. The next block is the Constant Modulus Adaptive (CMA) Equalizer block =-=[43]-=-, that tries to invert multipath so that the combination is a flat frequency response. The error value and tap update equations can be found in [43]. For DBPSK, the constellation diagram before and af...

Citation Context

... operate with an allocated amount of battery power. Their battery supply is very minimal as compared to other static nodes and hence must learn to cope up with small ratio of power for longer periods =-=[7]-=- . Hence, while considering the performance metric for the operation of a wireless network, it is essential that energy consumption be an important part of the analysis section. The radio transceiver ...

Citation Context

...sing high level language like Python[33] as a glue language, helps us in increasing the agility of software development. This is done by offloading most of the heavy processing work to be done by C++ =-=[34]-=- compiled code. Interoperation and data transfer between Python and Swig is managed by the Simple Wrapper Interface Generator (SWIG). Similar to any programming languages, GNU Radio uses a number of d...

Citation Context

...the development and research process faster and cheaper by giving way to the rapid variations in configurable prototypes. The concept of Software defined radios was basically introduced in the 1970’s =-=[29]-=-. It was initially used for defense communication by the U.S Department of Defense Office and was later adopted by commercial communication systems for research and development [28]. The conceptual di...

Citation Context

... its nearest constellation point. The frequency and phase of the NCO are updated according to this error. The symbol synchronization is done using a modified Mueller and Muller circuit from the paper =-=[44]-=-. This circuit interpolates the down-converted sample (using the NCO developed by the Costas loop) every mu samples, then it finds the sampling error based on this and the past symbols and the decisio...

Citation Context

...rformance improvement, noise reduction etc. SDR is characterized by increased flexibility and even slight modifications in the software programs can considerably change the functionality being tested =-=[26, 27]-=-. Hence, this satisfies the operating needs of individual applications. This helps in minimizing the hardware change for small changes in overall functionality. Many of the mathematical functions can ...

Citation Context

...cond block is the OFDM symbol synchronization defined in the file ofdm sync pn.py. This block is responsible for timing synchronization and frequency error correction based on Schmidl and Cox’ theory =-=[40]-=-. Here, the synchronization is based on PN sequence correlation. To achieve timing synchronization, good correlation property is required and hence PN sequence is used for preambles. The third block i...

Citation Context

...uced in the 1970’s [29]. It was initially used for defense communication by the U.S Department of Defense Office and was later adopted by commercial communication systems for research and development =-=[28]-=-. The conceptual diagram of SDR is shown in Fig. 4.1. Figure 4.1. Conceptual Diagram of Software defined radio 21 4.0.1. Basic Principle of SDR. The basic principle of Software defined radios is minim...

Citation Context

...ike environment without hardware. GNU Radio is primarily developed using the GNU/Linux operating system, but, Mac OS and Windows are also supported. 23 4.1.1. Concept of GNU Radio Flowgraph. GNU Radio=-=[31]-=- is a signal processing package, which is distributed under the terms of the GNU General Public License. In GNU Radio, a radio system is defined as a directed flow graph as in Fig. 4.3, where the grap...

Citation Context

...ario. But, practical wireless network has mostly inelastic form of traffic that varies significantly from TCP-like traffic. Mobile wireless sensor networks, as shown in Fig. 1.1, have many advantages =-=[11]-=- over the conventional static network. There is a common misconception that the static network is more secure because of its known location, which can be protected. A mobile node’s position is hard to...

Citation Context

...ogramming language, while the signal processing blocks are written in C++ using processor floating point extensions. This helps us develop real-time applications. Using high level language like Python=-=[33]-=- as a glue language, helps us in increasing the agility of software development. This is done by offloading most of the heavy processing work to be done by C++ [34] compiled code. Interoperation and d...

Citation Context

... . . . . . . . . . . . . . . . . . . . 23 4.4 Universal Software Radio Peripheral 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.5 WBX Transceiver Daughterboard =-=[37]-=- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4.6 DBPSK Modulation Block data flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....