scholarly journals Performance Analysis and Comparison of Full Chip and Half Chip Rate DC and NC Code Acquisition in MIMO DSCDMA over Uncorrelated Rayleigh Wireless Channel

2011 ◽  
Vol 2011 ◽  
pp. 1-8
Author(s):  
N. Sathish Kumar ◽  
K. R. Shankar Kumar
Keyword(s):  
Performance Analysis ◽  
Spread Spectrum ◽  
Performance Metrics ◽  
Multiple Input Multiple Output ◽  
Direct Sequence Spread Spectrum ◽  
Wireless Channel ◽  
Acquisition Time ◽  
Code Acquisition ◽  
Nc Code ◽  
Input Multiple Output

This paper presents the performance analysis and comparison of full chip and half chip rate of noncoherent (NC) and differentially coherent (DC) code acquisition scheme in (multiple input-multiple output) MIMO assisted by direct sequence spread spectrum (DS-CDMA) wireless system when communicated over uncorrelated Rayleigh channel. Four schemes are investigated, namely, SISO with full chip rate, SISO with Half chip rate, MIMO with full chip rate, and MIMO with half chip rate by varying the code acquisition technique. The simulation is done in RF signal processing Lab using matlab tool box, and the performance metrics are considered, namely, Bit Error Rate (BER) and mean acquisition time (MAT). The simulation results indicate that DC performance is superior than NC in both full chip and half chip rate and also shown that half chip performance is better than full chip in both DC and NC code acquisition methods.

scholarly journals Analisis Unjuk Kerja Convolutional Code pada Sistem MIMO MC-DSSS Melalui Kanal Rayleigh Fading

2017 ◽  
Vol 16 (2) ◽  
pp. 66 ◽  
Author(s):  
Kadek Agus Mahabojana Dwi Prayoga ◽  
Ni Made Ary Esta Dewi Wirastuti ◽  
I Gst A. Komang Diafari Djuni Hartawan
Keyword(s):  
Spread Spectrum ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Convolutional Code ◽  
Multiple Input Multiple Output ◽  
Density Ratio ◽  
Direct Sequence Spread Spectrum ◽  
Noise Power ◽  
Noise Power Spectral Density ◽  
Input Multiple Output

Kombinasi antara sistem MIMO (multiple input multiple output), OFDM (orthogonal frequency division multiplexing), dan spread spectrum serta adanya teknik pengkodean kanal mampu mengurangi efek fading dan error yang terjadi. Penelitian ini bertujuan untuk mengetahui perbandingan performansi dari sistem MIMO MC-DSSS (multi carrier-direct sequence spread spectrum) Uncoded atau tanpa pengkodean kanal dan MIMO MC-DSSS Convolutional Code atau dengan pengkodean kanal Convolutional yang melalui kanal Rayleigh Fading, ditinjau dari nilai dan grafik BER (bit error rate) berbanding Eb/No (energy per bit to noise power spectral density ratio). Penelitian ini menggunakan metode simulasi dengan menggunakan program Matlab R2015a. Hasil dari simulasi didapat unjuk kerja sistem MIMO MC-DSSS dengan Convolutional Code memiliki hasil yang lebih baik dari MIMO MC-DSSS. Pada kanal transmisi Rayleigh Fading untuk mencapi nilai BER sebesar 10-3 pada sistem MIMO MC-DSSS dengan Convolutional Code dibutuhkan Eb/No sebesar -7 dB. Sedangkan pada sistem MIMO MC-DSSS dibutuhkan Eb/No sebesar -3 dB.[turnitin 20%, 7-11-2016]

scholarly journals MIMO Self-Encoded Spread Spectrum with Iterative Detection over Rayleigh Fading Channels

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Shichuan Ma ◽  
Lim Nguyen ◽  
Won Mee Jang ◽  
Yaoqing (Lamar) Yang
Keyword(s):  
Fading Channels ◽  
Spread Spectrum ◽  
Rayleigh Fading ◽  
Mimo Systems ◽  
Signal To Noise Ratio ◽  
Multiple Input Multiple Output ◽  
Spatial Diversity ◽  
Iterative Detection ◽  
Channel Fading ◽  
Input Multiple Output

Self-encoded spread spectrum (SESS) is a novel communication technique that derives its spreading code from the randomness of the source stream rather than using conventional pseudorandom noise (PN) code. In this paper, we propose to incorporate SESS in multiple-input multiple-output (MIMO) systems as a means to combat against fading effects in wireless channels. Orthogonal space-time block-coded MIMO technique is employed to achieve spatial diversity, and the inherent temporal diversity in SESS modulation is exploited with iterative detection. Simulation results demonstrate that MIMO-SESS can effectively mitigate the channel fading effect such that the system can achieve a bit error rate of with very low signal-to-noise ratio, from 3.3 dB for a antenna configuration to just less than 0 dB for a configuration under Rayleigh fading. The performance improvement for the case is as much as 6.7 dB when compared to an MIMO PN-coded spread spectrum system.

Compact four-port vertically polarized UWB monopole antenna for MIMO communications

Circuit World ◽  
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Premalatha J. ◽  
Sheela D.
Keyword(s):  
Antenna Array ◽  
Performance Metrics ◽  
Multiple Input Multiple Output ◽  
Unit Cell ◽  
Ultra Wideband ◽  
Mimo Communications ◽  
Content Type ◽  
Directional Radiation ◽  
Multiple Input ◽  
Input Multiple Output

Purpose This paper aims to present the design of a compact vertically polarized four-element UWB antenna suitable for MIMO communications. Design/methodology/approach The unit cell antenna is constructed using a square ring radiator excited through a stepped impedance feed. The proposed antenna covers the Ultra-wideband (UWB) spectrum ranging from 2.2 to 12.3 GHz. The isolation between the unit cell antennas in the array is enhanced using a simple microstrip line resonator. The decoupling element is connected to the ground through a via. Findings The proposed scheme offers at least 16 dB improvement in the port-to-port coupling. Furthermore, the four-element antenna array is constructed using a specific interlocking scheme. The proposed antenna array’s Multiple Input Multiple Output (MIMO) performance metrics are analyzed. Originality/value By suitably selecting the excitation port, directional radiation patterns can be realized. The combined radiation pattern covers 360 degrees. A prototype antenna array is fabricated, and the simulation results are verified using real-time experiments. The proposed antenna is a suitable candidate for shark fin housing in automotive communications.

scholarly journals SPARX, a MIMO Array for Ground-Based Radar Interferometry

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 252 ◽  
Author(s):  
Alberto Michelini ◽  
Francesco Coppi ◽  
Alberto Bicci ◽  
Giovanni Alli
Keyword(s):  
Multiple Input Multiple Output ◽  
Mimo Radar ◽  
Sar Interferometry ◽  
Open Pit ◽  
Acquisition Time ◽  
Atmospheric Effects ◽  
Mechanical Assembly ◽  
Input Multiple Output ◽  
Virtual Array ◽  
Interferometric Sar

Ground-Based SAR Interferometry (GB-InSAR) is nowadays a proven technique widely used for slope monitoring in open pit mines and landslide control. Traditional GB-InSAR techniques involve transmitting and receiving antennas moving on a scanner to achieve the desired synthetic aperture. Mechanical movement limits the acquisition speed of the SAR image. There is a need for faster acquisition time as it plays an important role in correcting rapidly varying atmospheric effects. Also, a fast imaging radar can extend the applications to the measurement of vibrations of large structures. Furthermore, the mechanical assembly put constraints on the transportability and weight of the system. To overcome these limitations an electronically switched array would be preferable, which however faces enormous technological and cost difficulties associated to the large number of array elements needed. Imaging Multiple-Input Multiple Output (MIMO) radars can be used as a significant alternative to usual mechanical SAR and full array systems. This paper describes the ground-based X-band MIMO radar SPARX recently developed by IDS GeoRadar in order to overcome the limits of IDS GeoRadar’s well-established ground based interferometric SAR systems. The SPARX array consists of 16 transmit and 16 receive antennas, organized in independent sub-modules and geometrically arranged in order to synthesize an equally spaced virtual array of 256 elements.

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