scholarly journals Downlink Steered Space-Time Spreading Assisted Generalised Multicarrier DS-CDMA Using Sphere-Packing-Aided Multilevel Coding

2007 ◽  
Author(s):  
Mohammed El-Hajjar ◽  
Ronald Y. S. Tee ◽  
Hu Bin ◽  
Lie-Liang Yang ◽  
Lajos Hanzo
Keyword(s):  
Sphere Packing ◽  
Space Time ◽  
Multilevel Coding

scholarly journals A Turbo Detection and Sphere-Packing-Modulation-Aided Space-Time Coding Scheme

2007 ◽  
Vol 56 (2) ◽  
pp. 575-582 ◽  
Author(s):  
Osamah Rashed Alamri ◽  
Bee Leong Yeap ◽  
Lajos Hanzo
Keyword(s):  
Sphere Packing ◽  
Space Time ◽  
Space Time Coding ◽  
Coding Scheme ◽  
Turbo Detection ◽  
Time Coding

scholarly journals Performance Analysis of Iteratively Decoded Convergent Source Mapping with Sphere Packing-Assisted Differential Space-Time Spreading Technique for Efficient Video Transmission

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Ishtiaque Ahmed ◽  
Nasru Minallah ◽  
Jaroslav Frnda ◽  
Jan Nedoma
Keyword(s):  
Information Transfer ◽  
Video Transmission ◽  
Hamming Distance ◽  
Signal To Noise Ratio ◽  
Sphere Packing ◽  
Space Time ◽  
Data Partitioning ◽  
Video Codec ◽  
Efficient System ◽  
Data Rates

With the substantial growth in number of wireless devices, future communication demands overarching research to design high-throughput and efficient systems. We propose an intelligent Convergent Source Mapping (CSM) approach incorporating Differential Space-Time Spreading (DSTS) technique with Sphere Packing (SP) modulation. The crux of CSM process is assured convergence by attaining an infinitesimal Bit-Error Rate (BER). Data Partitioning (DP) H.264 video codec is deployed to gauge the performance of our intelligent and efficient system. For the purpose of efficient and higher data rates, we have incorporated compression efficient source encoding along with error resiliency and transmission robustness features. The proposed system follows the concept of iterations between the Soft-Bit Source-Decoder (SBSD) and Recursive Systematic Convolutional (RSC) decoder. Simulations of the DSTS-SP-assisted CSM system are presented for the correlated narrowband Rayleigh channel, using different CSM rates but constant overall bit-rate budget. The SP-assisted DSTS systems are mainly useful in decoding algorithms that operate without requiring Channel State Information (CSI). The effects of incorporating redundancy via different CSM schemes on the attainable performance and convergence of the proposed system are investigated using EXtrinsic Information Transfer (EXIT) charts. The effectiveness of the proposed system is demonstrated through IT++ based proof-of-concept simulations. The Peak Signal-to-Noise Ratio (PSNR) analysis shows that using Rate-2/6 CSM with minimum Hamming distance ( d H , min ) of 4 offers about 5 dB gain, compared to an identical overall system code rate but with Rate-2/3 CSM and d H , min of 2. Furthermore, for a consistent value of d H , min and overall rate, the Rate-2/3 CSM scheme beats the Rate-5/6 CSM by about 2 dB at the PSNR degradation point of 2 dB. Moreover, the proposed system with Rate-2/3 CSM scheme furnishes an E b / N 0 gain of 20 dB when compared with the uniform-rate benchmarker. Clearly, we can say that higher d H , min and lower CSM values are favourable for our proposed setup.

On performance limits of space-time codes: a sphere-packing bound approach

2003 ◽  
Vol 49 (10) ◽  
pp. 2681-2687 ◽  
Author(s):  
M. Fozunbal ◽  
S.W. McLaughlin ◽  
R.W. Schafer
Keyword(s):  
Sphere Packing ◽  
Space Time ◽  
Performance Limits ◽  
Space Time Codes
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