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Performance evaluation of open loop multi-user MIMO systems

S. Naga Sekhar Kshatriya, Sivakishore Reddy Yerrapareddy, Kiran Kuchi, Giridhar Krishnamurthy
2011 2011 National Conference on Communications (NCC)  
Significant throughput gains can be achieved in a multi-user MIMO (MU-MIMO) wireless system by exploiting the combination of multi-user scheduling and multi-user diversity. Open-loop MU-MIMO (OL-MU-MIMO) is a codebook based precoding technique where precoders are fixed a priori at the base station (BS) in a known fashion and the user needs to feedback which precoding vector is to be chosen referred to as precoding vector index (PVI) or stream indicator. This scheme feedbacks the channel quality
more » ... indicator (CQI) which is used by the BS for allocation of modulation and coding scheme (MCS) to the scheduled users. As the precoders used at all the base stations are known a priori, estimation of co-channel interference (CCI) is accurate and there is negligible mismatch between the CQI fed back by the user in present frame and SINR experienced by the user during next frame for low Doppler, resulting in stable CQI modeling. In this paper, an extensive study is made on OL-MU-MIMO and open loop single-user MIMO (OL-SU-MIMO), with an emphasis on how OL-MU-MIMO exploits multi-user diversity to achieve high spectral efficiencies. We also derive the SINR and CQI expressions for such MU-MIMO systems, and provide simulation results which indicate that OL-MU-MIMO outperforms OL-SU-MIMO only when there are large number of users in the system.
doi:10.1109/ncc.2011.5734749 fatcat:lso2bwhetfe3ljnzvuj5okt7za

Distributed downlink Multi-Cell Processing requiring reduced-rate back-haul data exchange

Rong Zhang, Krishnamurthy. Giridhar, Lajos Hanzo
2011 2011 IEEE Wireless Communications and Networking Conference  
Different-complexity Multi-Cell Processing (MCP) schemes employing Distributed Signal-to-Interference-Leakageplus-Noise-Ratio (SILNR) precoding techniques are proposed, which require reduced back-haul data exchange in comparison to the conventional MCP structure. Our results demonstrate that the proposed structures are capable of increasing the achievable cell-edge throughput and offering different geographic rate profile distributions as well as meeting different delay requirements.
doi:10.1109/wcnc.2011.5779343 dblp:conf/wcnc/ZhangGH11 fatcat:7hz2vkma7fc6hkqt2nlyyavc4a

Novel 3-Stage Scheduler for Real Time Traffic in an OFDMA System with Delay and Retransmission Constraints

Suman Kumar, Krishnamurthy Giridhar, Sheetal Kalyani
Emerging wireless communication systems use MIMO-OFDM with adaptive modulation and Hybrid Automatic Repeat Request (HARQ) techniques to enables high bit rate and low packet error rate. In this work, a 3-Stage packet scheduling algorithm that is HARQ aware is proposed, which supports real time service with multi-level delay constraints and retransmission constraints in OFDM systems. For performance analysis, three Quality of Service (QoS) parameters namely packet loss rate, fairness, and
more » ... ut are studied. Corresponding to these three metrics and depending upon the delay and retransmission constraints, a 3-Stage scheduling strategy is proposed. It is assumed that the packets are lost due to violation of the delay constraint and/or channel induced error, even after allowing the maximum number of retransmissions. Simulation result shows that this novel 3-Stage scheduler achieves a balance between the three QoS metrics, and could therefore be preferred over Modified Largest Weighted Delay First, Proportion Fair, and Max Rate schedulers, which can not simultaneously satisfy all the three QoS metrics.


2005 Translation Today  
As Jiddu Krishnamurthy put it, "there is in every one of us the rest of humanity".  ...  As Jiddu Krishnamurthy would say, anything that separates the self from the other (outside the self) is ill-founded.  ...  Giridhar  ... 
doi:10.46623/tt/2005.2.1.ed fatcat:qjhv7hsx3vgdxhns22t7hvjrpa

Comparative Study of Landsat and Aster Data by Morphometric Analysis

Sujit Kumar, Tapasi Bhandary
2015 Civil Engineering Journal  
Giridhar, and G. K. Viswanadh. "Watershed delineation and stream network analysis uisng gis." and 4 shows delineated watershed of both of the Aster and Landsat DEM data.  ...  The basin morphometric characteristics of the various basins have been studied by many scientists using conventional (Horton, 1945; Smith, 1950; Strahler, 1957) and remote sensing and GIS methods (Krishnamurthy  ... 
doi:10.28991/cej-2015-00000007 fatcat:h47yls7upve2zgbvlghll2edhm

Effect of Micronutrients and Biofertilizers on Growth and Yield of Mulberry (Morus indica L.) and Silkworm (Bombyx mori L.)

Nazar, M.K. Kalarani, P. Jeyakumar, T. Kalaiselvi, K. Arulmozhiselvan, S. Manimekalai
2019 Madras Agricultural Journal  
Hence improvement of mulberry leaf quality and quantity is essential (Chaudhary and Giridhar, 1987) .  ...  Better response could be attributed to better nutritive value of leaves resulting in better silkworm cocoon yield and quality (Vishwanth and Krishnamurthy, 1984; Sinha et al., 2006) .  ... 
doi:10.29321/maj.2019.000224 fatcat:mv7ykpq2arayxl4bvt4hr5vkl4

Plant Somatic Embryogenesis: Some Useful Considerations [chapter]

Antonia Gutirrez-Mora, Alejandra Guillermina, Benjamn Rodrguez-Garay, Azucena Ascencio-Cabral, Lin Li-Wei
2012 Embryogenesis  
Br and Phalaenopsis in MS medium supplemented with BA (Mohan & Krishnamurthy, 2002; Rey & Mroginski, 2006; Jha et al., 2009; Gow et al., 2010) .  ...  Ethylene biosynthesis Another factor affecting somatic embryogenesis is ethylene biosynthesis which has been reported to inhibit regeneration (Giridhar et al., 2004) , it has been reported that by blocking  ... 
doi:10.5772/36345 fatcat:rfcqrhfswrbrzficrhrurrlp7m

Micropropagation of Caralluma stalagmifera var. longipetala: A rare succulent medicinal plant from Karnataka, India

Naik M. Ramachandra, Karuppusamy Subbiah, L. Krishnamurthy Y.
2014 African Journal of Biotechnology  
., 2003) and Decalepis hamiltonii (Giridhar et al., 2005) .  ... 
doi:10.5897/ajb2014.13852 fatcat:jnmceo5xrzefbjjzz7mzsbkrre

Significant Role of Perovskite Materials for Degradation of Organic Pollutants [chapter]

Someshwar Pola, Ramesh Gade
2020 Perovskite and Piezoelectric Materials [Working Title]  
Journal of Hazardous Materials. 2009;162:899-905 [59] Gomathi Devi L, Krishnamurthy G.  ...  International Journal of Hydrogen Energy. 2014;39:13481-13485 [58] Gomathi Devi L, Krishnamurthy G.  ... 
doi:10.5772/intechopen.91680 fatcat:w7qqa2smdffxbbbp5ekkm555ba

Author Index

2014 Proceedings of the Indian Academy of sciences. Chemical sciences  
Correlation between carbon-carbon bond length and the ease of retro Diels-Alder reaction 1369 Kothurkar N K see Yamuna R 75 Kottalanka R K see Panda T K 1463 Krishna Reddy J see Hari Padmasri A 387 Krishnamurthy  ...  calcium phosphate 649 Baishya A see Biswal H S 1781 see Nembenna S 1781 Bajpai A see Moorthy J N 1323 Bakardjieva S see Labhsetwar N 517 Balachandran C see Perumal P T 177 Balaji S S see Giridhar  ... 
doi:10.1007/s12039-015-0766-5 fatcat:fvwhltszuned7jlkrb4t7kquci

Prevalence of myopia in Indian school children: Meta-analysis of last four decades

Divya Agarwal, Rohit Saxena, Vivek Gupta, Kalaivani Mani, Rebika Dhiman, Amit Bhardawaj, Praveen Vashist, William Joe
2020 PLoS ONE  
Dandona R, Dandona L, Srinivas M, Giridhar P, McCarty CA, Rao GN. Population-based assessment of refractive error in India: the Andhra Pradesh eye disease study.  ...  Krishnamurthy H, Tanushree V¸D'Silva AJ, Mobin G, Kantharaju KP. Prevalence of refractive errors among school children of 5-15 years age group in Mysore district. Int J Sci Stud 2014; 2(8):150-154.  ... 
doi:10.1371/journal.pone.0240750 pmid:33075102 fatcat:aobraujg4bdkrahyhagbb54c2e

Organogenesis from in vitro-derived leaf and internode explants of Hoya wightii ssp. palniensis -a vulnerable species of Western Ghats

Subbaiah Revathi Lakshmi, Jambarapu Herald Franklin Benjamin, Tirupathi Senthil Kumar, Garimella Venkata Suryanarayana Murthy, Mandali Venkateswara Rao
2013 Brazilian Archives of Biology and Technology  
Shoot regeneration from in vitro derived explants have been reported in other plants such as Decalepis hamiltonii by Giridhar et al. (2004) ; Vaccinium corymbosum (Billings et al. 1988) ; Pyrus communis  ...  explant of Momordica cymbalaria (Nikam et al. 2009 ); Elaeagnus angustifolia (Karami and Piri 2009 ) and from internode of Withania somnifera (Kulkarni et al. 2000) and Piper colubrinum (Kelkar and Krishnamurthy  ... 
doi:10.1590/s1516-89132013000300010 fatcat:6h426hyonraq5c7i2ildowpdvi

Effect of Plant Geometry and Nutrition on Growth, Parameters of Transplanted Ajowan (Trachyspermum ammi L. Sprague) in the Red Loamy Soils of Andhra Pradesh, India

H. S. Kiran, M. Lakshminarayana Reddy, K. Giridhar, S. Surya Kumari, D. R. Salomi Suneetha
2020 International Journal of Current Microbiology and Applied Sciences  
., (2002) in fennel, Krishnamurthy et al., (2000) , Premnath et al., (2008) and Naruka et al., (2012) in ajowan.  ... 
doi:10.20546/ijcmas.2020.907.101 fatcat:cmczoaawg5eihltttkzrpdzyja

Robust and Efficient Swarm Communication Topologies for Hostile Environments [article]

Vipul Mann, Abhishek Sivaram, Laya Das, Venkat Venkatasubramanian
2020 arXiv   pre-print
Giridhar, Balachandra B. Krishnamurthy, Chunhua Zhao, Priyan R. Patkar, and Santhoji Katare.  ... 
arXiv:2008.09575v1 fatcat:abp2objhbfhwnnzciib6is3zm4


Akshatha Venugopalan, P Giridhar, G Ravishankar
2011 Indian Journal of Fundamental and Applied Life Sciences   unpublished
Krishnamurthy and Giridhar (1976) used the water soluble annatto dye in orange squash, synthetic syrup, mango pulp and tomato ketchup, and found that the colour is stable for a period of 2 months.  ...  It was also shown that using abiotic elicitors as a tool to improve the annatto pigment yield on standing crop (Giridhar and Parimalan 2010) is feasible.  ... 
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