19-04-2014, 10:49 AM
ADPATIVE AND RECONFIGURABLE CODING AND MODULATION IN 3G WIRELESS Networks
ADPATIVE AND RECONFIGURABLE .pptx (Size: 367.61 KB / Downloads: 16)
BACKGROUND
W-CDMA is being used by Universal Mobile Telecommunication System (UMTS) as platform of the 3rd generation cellular communication system.
High data rate signal transmission can be transmitted over the air by using W-CDMA system, thus enabling of multimedia rich applications such as video streams and high resolution pictures to end users.
WHY 3G NETWORK?
In 2G networks, GMSK modulation scheme is widely used in GSM (Global System for Mobile Communication). This modulation can only transmit data rate of 1 bit per symbol. So it is quite sure that this kind of modulation scheme is not suitable for the next generation communication system.
ABSTRACT
The transmission from base station (bts) to mobile or downlink transmission using M-ary Quadrature Amplitude modulation (QAM) and Quadrature phase shift keying (QPSK) modulation scheme are consider in W-CDMA system. We can analysis the performance of these modulation techniques when the system is subjected to AWGN and multipath Rayleigh fading are consider in the channel. We will use MatLab 7.10 for simulation and evaluation of BER and SNR for W-CDMA system models.
CREATING NEW FUNCTIONS LIBRARY IN MATLAB
Developing the analysis Algorithms between BER and SNR of the WCDMA System, it is necessary to create the function which is further adding in the library of the Matlab to make the directory.
Autocoor.m,mseq.m,spread.m,qammod.m,qpskmod.m,qamdemod.m,qpskdemode.m,
oversampling.m,filter.m,fade.m,hrolloffcoef.m
CONCLUSION
In telecommunication field the major challenges is to convey the information as efficiently as possible through limited bandwidth, though the some of information bits are lost in most of the cases and signal which is sent originally will face fading. To reduce the bit error rate the loss of information and signal fading should be minimized.
In our thesis we analyze two modulation techniques, QPSK and 16-QAM to reduce the error performance of the signal and compare which technique is better through Rayleigh Fading Channel in the presence of AWGN.