Volume 9, Issue 2, July 2011


Design, Simulation and Implementation of a MIMO MC-CDMA based trans-receiver system [Full Text]
 
Sayan Dey, Supratim Dutta and Souradipa Das

Abstract—The  advent  of  modern  communication  techniques  have  been  providing  users  efficient,  highly  secure  and  extremely  fast  tech-niques of communication.  Digital  communication started  with  techniques like Amplitude Shift Keying  (ASK),  Frequency  Shift  Keying (FSK), GMSK  (Gaussian  Mean  Shift  Keying).Techniques  like  FDM  (Frequency  Division  Multiplexing)  and  TDM  (Time  Division  Multiplexing)  were highly  used  in  commercial  communication  systems.  Modern  techniques  like  OFDM  (Orthogonal  Frequency  Division  Multiplexing)  and  MC-CDMA (Multi Carrier Code Division Multiple Access) provided appreciable faster, reliable and secure data transfer. This paper puts forward an innovative,  highly  precise  and  successful  technology  for  data  transfer  implementing  the  MIMO  (Multiple  input  multiple  output)  based  MC-CDMA modulation technique. MC-CDMA modulation is efficient, secure and cheaper compared to FDM and TDM.A design and implementa-tion of a low cost low power MIMO based  MC-CDMA transmitter-receiver system has been put forward in this paper which uses an advanced and less complex algorithm which reduces the computational complexity and VLSI design and implementation  complexity. Results obtained implementing this design in a FPGA kit confirm the highly efficient data transfer rate, the considerably negligible error rates and considerably low power consumption by the system.

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The Next Generation of Sensor Node in Wireless Sensor Networks [Full Text]

S.Charoenpanyasak and W.Suntiamorntut

Abstract—
Wireless sensor networks are widely used in data gathering applications from the environmental to the health care system.  This  type  of  networks  composes  of  a  large  amount  of  tiny  and  cheap  devices  called  node.  The  challenge  of  node development is posed for designer such as energy usage, processing power, memory size and sensing capability. The original node architecture  has  been  developed for  many  years. It  consists of  microcontroller,  memory,  radio  module and  sensing  unit. Wireless sensor  network  applications  become more  complex  and  more computing-intensive. The  existing node  may  not  be  a good choice for a battery-limited device likes sensor node. This paper presents a survey of modern sensor nodes. We suggest the next generation of sensor node based on the dynamically partial reconfigurable hardware. 

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Detection of Optimally Quantized CDMA Signals in Rayleigh Channel [Full Text]

Manish D. Sawale and R. N. Yadav

Abstract—
This paper provides design and analysis of detection of optimally quantized CDMA signals in Rayleigh channel. The performance of the method is analyzed for different combination of random/fixed data with random/fixed PN sequences. The Bit Error Rate (BER) results of proposed method are compared with the theoretical BER of received signals, which reveals that the performance of the proposed method approaches the theoretical BER curve as the SNR increases. The optimum quantization is achieved using minimization of expected distortion of received signal. The distortion values of normal quantization are compared with optimal quantization and the results shows that optimal quantization performs better than normal quantization. The perfor-mance comparison of BER for different sets of users is also evaluated at different SNRs.

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A Novel Technique of Fingerprint Identification Based on Sectorization of Complex Walsh Plane
[Full Text]

Dr. H. B. Kekre, Dr. Tanuja K. Sarode and Rekha Vig

Abstract— 
In  this  paper  a  new  method  for  fingerprint  identification  has  been  described. This  method  treats  the  digitized fingerprint images in transform domain using well known Walsh transform.To map these coefficients onto two dimentional plane, we have proposed complex Walsh Transform.  A sectorization algorithm, which creates sectors of the complex Walsh plane, is applied  to  the  image  transforms,  which  helps  in  generating  the  feature  vectors  of  the  images.  The  feature  vector  (set  of features)  of  a  test  image  is  compared  with  those  stored  in  the  database  and  a  match  is  solicited.  This  algorithm  has  been implemented on a database of 168 fingerprint images and  the  measures  GAR(Genuine Acceptance  Rate), FRR(False Reject Rate) and average number of matches calculated show that this algorithm though simple can be effectively used in Automated Fingerprint Identification Systems.