scholarly journals Performance of Different Concatenated Coding Schemes for CDMA System

2018 ◽  
Vol 24 (12) ◽  
pp. 60-72
Author(s):  
Zainab Majeed Abid
Keyword(s):  
Channel Coding ◽  
Fading Channel ◽  
Convolutional Code ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Cdma System ◽  
Concatenated Coding ◽  
Multipath Fading Channel ◽  
Outer Code ◽  
Serially Concatenated

In this paper different channel coding and interleaving schemes in DS/CDMA system over multipath fading channel were used. Two types of serially concatenated coding were presented. The first one composed of Reed-Solomon as outer code, convolutional code as inner code and the interleaver between the outer and inner codes and the second consist of convolutional code as outer code, interleaved in the middle and differential code as an inner code. Bit error rate performance of different schemes in multipath fading channel was analyzed and compared. Rack receiver was used in DS/CDMA receiver to combine multipath components in order to enhance the signal to noise ratio at the receiver.  

An Improved Data-Aided Symbol Timing Algorithm for OFDM Systems

2011 ◽  
Vol 403-408 ◽  
pp. 1568-1571
Author(s):  
Xiao Yan Zhao
Keyword(s):  
Fading Channel ◽  
Orthogonal Frequency Division Multiplexing ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Ofdm Systems ◽  
Multipath Fading Channel ◽  
Symbol Synchronization ◽  
Timing Errors ◽  
Symbol Timing ◽  
Training Symbol

Synchronization is very important to orthogonal frequency division multiplexing (OFDM) systems. Taking aim at the problem that the timing inaccuracy of the S&C method and the indistinct peak of the timing metric produced by Park method under the low signal-to-noise ratio (SNR) and fading channel, a new symbol synchronization algorithm based on the training symbol is proposed in this paper. The new algorithm exploits the training symbol proposed by S&C to correlate the received signal with the known training symbol again at the receiving end to identify the start point of the OFDM symbol. The result of the simulation shows that the proposed method’s timing metric is of the impulse-shaped peak under the condition of the lower SNR and multipath fading channel, and has smaller timing errors compared with the conventional method in terms of mean-square error (MSE) of the timing estimator.

Performance Analysis of MT-CDMA System with Antenna Array in a Multipath Fading Channel

2006 ◽  
Vol 41 (3) ◽  
pp. 427-446 ◽  
Author(s):  
Wei Yang ◽  
Junying Liu ◽  
Junshi Chen ◽  
Zhenhui Tan ◽  
Shixin Cheng
Keyword(s):  
Performance Analysis ◽  
Antenna Array ◽  
Fading Channel ◽  
Multipath Fading ◽  
Cdma System ◽  
Multipath Fading Channel

ROBUST JPEG2000 IMAGE TRANSMISSION THROUGH LOW SNR MULTI-CARRIER CDMA SYSTEM IN FREQUENCY-SELECTIVE RAYLEIGH FADING CHANNELS: A PERFORMANCE STUDY

2011 ◽  
Vol 09 (02) ◽  
pp. 283-303 ◽  
Author(s):  
KATHIYAIAH THIYAGU ◽  
T. H. OH
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Image Transmission ◽  
Multipath Fading ◽  
Cdma System ◽  
Performance Study ◽  
Compression Technique ◽  
Multipath Fading Channel ◽  
Low Snr ◽  
Code Division Multiple

The demand for high data rate transmission is ever increasing every day. Multi-carrier code division multiple access (MC-CDMA) system is considered as the forerunner and advancement in the mobile communication system. In this paper, two types of JPEG2000 lossily-compressed test images are transmitted through an MC-CDMA channel in low SNR (as low as 4 dB) environment and their quality are evaluated objectively by using peak signal-to-noise ratio (PSNR) and root mean square error (RMSE). The test images are all compressed from ratio of 10 : 1 up to 70 : 1 and the system involves multi-user image transmission in near real-time low SNR (±5 dB). It is found that JPEG2000 image compression technique that applies wavelet transform performed quite well in the low SNR multipath fading channel — as low as 4 dB, and this looks promising for future applications.

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