- Machine Learning, Deep learning
- Compressed Sensing and Sparse Signal Processing

with applications to

- 5G Wireless Systems
- Radar Systems
- Autonomous Navigation
- MRI Signal Processing
- Health Care
- Neuroscience

Class Timings: Tue, Thu 0830-1000 (online)

Scope: Review of estimation theory. Wiener Solution. Kalman filter and its application to estimation, filtering and prediction. Method of steepest descent and its convergence criteria, least mean square gradient algorithm (LMS), criteria for convergence and LMS versions: normalized LMS, leaky, sign, variable step-size, transform domain LMS algorithm using DFT and DCT. Recursive least square (RLS) method, fast lattice RLS . Applications of adaptive filtering: spectral estimation, system identification, acoustic noise cancellation, wireless channel equalization, radar systems.

References : • Ali H Sayed, Adaptive Filters, John Wiley/IEEE, 2008

Previous Semester teaching:

Class Timings: Tue, Thu 0830-1000 (online)

Scope: This course will cover concepts related to the use of multiple sensors to solve problems related to

Direction of Arrival Estimation: Sensor array geometry, beamforming, subspace methods

MIMO Wireless Communication Systems: MIMO wireless channels, Capacity of MIMO Communication systems, MIMO OFDM systems, Spatial/Index modulation concepts, Physical layer algorithms for parameter estimation with reference to 5G systems; ‘

MIMO Radar systems: Introduction to radar systems, MIMO radar concepts and MIMO-OFDM radar systems, Dual Function Radar and Communication systems.

References include books and papers:

- Array Signal Processing: Concepts and Techniques by Dan E. Dudgeon and Don H. Johnson
- Spectral Analysis of Signals – P Stoica and R L Moses
- Detection, Estimation, and Modulation Theory, Optimum Array Processing by Harry L. Van Trees
- MIMO Radar Signal Processing – J Li and P Stoica

- Index Modulation Techniques
- Type II Channel State Information Feedback
- Wireless Channel Modelling of Drone -to-ground link

in collaboration with

- University of Bordeaux
- British Telecom Research
- Qualcomm
- University of Southampton

- Reducing readout time in an MRI machine using novel
*k*-space trajectory designs - Design of affordable and portable MRI machines

in collaboration with

- TU Delft

- AI/ML techniques for predicting patient’s state in an Intensive Care Unit of a hospital

in collaboration with

- Christian Medical College Vellore

- National dataset creation for Indian road conditions
- Deep Neural Networks for Collision avoidance in trucks operating in an open-cast mine

in collaboration with

- WIPRO
- VOLVO

- Understanding reading in the human brain

in collaboration with

- IISc colleagues

A Agrawal, KVS Hari, SP Arun, “Reading Increases the Compositionality of Visual Word Representations,” **Psychological Science **, Nov 2019

Development of an indigenous Continuous Glucose Monitoring and Control system in collaboration with

- IISc Colleagues
- Ramaiah Hosiptal, Bangalore

Building a chair for the elderly in collaboration with IISc Colleagues

Building a radar prototype for detecting drones

- Editor-in-Chief (Electrical Sciences)
- Information for Authors

** Join SPS – SPS Student Membership only $1**

Join SPS Member for only $11 (50% off in India)

**Vice President – Membership**(1 Jan 2020 – 31 Dec 2022)**Regional Director-at-Large**(1 Jan 2018 – 31 Dec 2019)

Member of IEEE Signal Processing Society’s Signal Processing Theory and Methods Technical Committee (SPTM-TC) (2014 – 2019).

- Associate Member of IEEE Signal Processing Society’s Sensor Array and Multichannel Technical Committee (SAM-TC) (2010 – Present).
- Vice-Chairman, IEEE Bangalore Section (2012, 2013)
- Chairman, IEEE Signal Processing Society Bangalore Chapter in 2005, 2011, 2012, 2013. Part of the Founding team of the Bangalore Chapter in 2001.

Active member of all activities of the Bangalore chapter in organizing International conferences (SPCOM series), SP-Connect, an activity for connecting students and technologists. - Reviewer of the papers submitted to IEEE journals (TSP, SPL, JSTSP) and IEEE conferences.

**FELLOW, IEEE**- Chair of the IEEE Ad-hoc committee on India Strategy (2017)
- Chairman, IEEE Bangalore Section, 2016
- Vice-Chairman, IEEE Bangalore Section (2012, 2013)
- Chairman, IEEE Signal Processing Society Bangalore Chapter in 2005, 2011, 2012, 2013. Part of the Founding team of the Bangalore Chapter in 2001. Active member of all activities of the Bangalore chapter in organizing International conferences (SPCOM series), SP-Connect, an activity for connecting students and technologists.
- General Chair, 2013 IEEE International Conference on Electronics, Computing and Communication Technologies (IEEE CONECCT), 17-19 Jan 2013.
- General Chair, 2014 IEEE International Conference on Electronics, Computing and Communication Technologies (IEEE CONECCT), 6-7 Jan 2014.
- Member, Industry Forum and Exhibition Committee, International Conference on Communications (ICC 2013), 9-13 June 2013, Budapest, Hungary
- Member of IEEE 802.16 working group in the IEEE Standards group. Initiated the work for IEEE 802.16 (WiMAX) standard on wireless channel models, 1999-2001.
- Member of the IEEE University Programs Ad-hoc Committee (UPC), IEEE Educational Activities Board (IEEE-EAB), USA. The mission of the UPC is “To promote and enhance the content and delivery of engineering education globally.” Nominee is the only member from India (2010 – present).
- Member of Technical Program Committees of several International conferences supported by IEEE like IEEE ICC, IEEE CONECCT, EUSIPCO, VTC, Pernets.
- Reviewer of the papers submitted to IEEE journals (TSP, SPL, JSTSP) and IEEE conferences.

- Dr Farhan Mukadam, MD (joined in 2019 as part of the IISc-CMC MD-PhD programme)
- Swati Bhattacharya (joined in 2019)
- Maria Francis (joined in 2019)
- G V V R Pavan Kumar (joined in 2019)
- B Satwika (joined in 2018)
- Shubham Sharma (joined in 2015), working on signal processing for affordable and portable MRI

SSP Lab webpage: ** **For details click here

Where am I? – An experiment in Indoor Positioning

**Click for Citations based on Google Scholar **

- Peter Joseph Basil Morris and K.V.S Hari, “Detection and Localisation of Unmanned Aircraft Systems (UAS) using Millimeter Wave (mmWave) Automotive RADAR Sensors,” IEEE Sensors Letters, Year: 2021, Early Access Article, DOI 10.1109/LSENS.2021.3085087
- Shubham Sharma, Mario Coutino, Sundeep Prabhakar Chepuri, Geert Leus, K V S Hari, “Towards a general framework for fast and feasible k-space trajectories for MRI based on projection methods, “
**Magnetic Resonance Imaging**, (72), pp. 122-134, Oct 2020.*(First author is a student and co-authors are collaborators)* - Aakash Agrawal, KVS Hari, SP Arun, “A compositional neural code in high-level visual cortex can explain jumbled word reading,”
**Elife**, (9), pp. e54846, May 2020.*(First author is a student and third author is a collaborator)* - A Agrawal, KVS Hari, SP Arun, “Reading Increases the Compositionality of Visual Word Representations,”
**Psychological Science**, Nov 2019.*(First author is a student and third author is a collaborator)* - Rakshith Rajashekar, M Di Renzo, Lie-Lang Yang, K.V.S. Hari, Lajos Hanzo, “A Finite Input Alphabet Perspective on the Rate-Energy Tradeoff in SWIPT Over Parallel Gaussian Channels,”
**IEEE Journal on Selected Areas in Communications**, vol. 37 (1), pp. 48-60, Jan 2019.*(First author was a former student and co-authors are collaborators)* - Rakshith Rajashekar, Lie-Lang Yang, K.V.S. Hari, Lajos Hanzo,” Transmit Antenna Subset Selection in Generalised Spatial Modulation Systems,”
**IEEE Transactions on Vehicular Technology**, vol. 68, pp. 1979-1983, Feb 2019.*(First author is a former student and co-authors are collaborators)* - Renu Jose and K.V.S. Hari, “Bounds and joint estimators for channel, phase noise, and timing error in communication systems using statistical framework,”
**Elsevier Computers and Electrical Engineering**, vol 72, pp. 431-442, Oct 2018.*(First author is a former student)* - Rakshith Rajashekar, Marco Di Renzo, K.V.S. Hari, Lajos Hanzo,” A Beamforming Aided Full Diversity Scheme for low-altitude air-to-ground communication systems operating with limited feedback”
**IEEE Transactions on Communications**, vol. 68, pp. 6602-6613, Dec 2018.*(First author is a former student and co-authors are collaborators)* - Rakshith Rajashekar, K.V.S. Hari, Lajos Hanzo,” Transmit Antenna Subset Selection for single and Multiuser Spatial Modulation Systems Operating in Frequency Selective Channels,”
**IEEE Transactions on Vehicular Technology**, vol.67(7), pp. 6156-6169, July 2018.*(First author is a former student and third author is a collaborator)* - Shubham Sharma and K.V.S. Hari, “Four-Shot non-Cartesian Trajectories in k-space Sampling in MRI,”
**CSI Transactions on ICT**(Springer), vol 6, issue 1, pp. 11-16, 2018.*(First author is a student)* - Rakshith Rajashekar, K.V.S. Hari, Lajos Hanzo,” Transmit Antenna Subset Selection in Spatial Modulation Relying on a Realistic Error-Infested Feedback Channel,”
**IEEE Access**, vol.6, pp.5879-5890, October 2017. - Rakshith Rajashekar, Marco Di Renzo, K.V.S. Hari, Lajos Hanzo, “A Generalized Transmit and Receive Diversity Condition for Feedback-Assisted MIMO Systems: Theory and Applications in Full-Duplex Spatial Modulation,”
**IEEE Transactions on Signal Processing,**vol. 64, pp. 6505-6519, Dec 2017.*(First author is a former student and co-authors ar collaborators)* - Rakshith Rajashekar, Chao Xu, Naoki Ishikawa, S Shinya Sugiura, K.V.S. Hari, L. Hanzo, ” Algebraic Differential Spatial Modulation is Capable of Approaching the Performance of its Coherent Counterpart”,
**IEEE Transactions on Communications.**vol. 65(10), pp.4260-4273, Oct 2017.*(First author is a former student and co-authors are collaborators)* - Avik Santra and K.V.S. Hari, “A Novel Subspace Based Method for Compensation of Multiple CFOs in uplink MIMO OFDM Systems”,
**IEEE Communication Letters.**vol. 21(9), pp. 1993–1996, Sep 2017.*(First author is a former student)* - Renu Jose and K.V.S. Hari, “Joint Statistical Framework for the Estimation of Channel and SFO in OFDM Systems,”
**IET Signal Processing**, Jun 2017. DOI: 10.1049/iet-spr.2016.0580.*(First author is a former student.)* - A. R. Sachin, Sooraj K. Ambat and K.V.S. Hari, “Analysis of Intra-Pulse Frequency Modulated, Low Probability of Interception, Radar Signals,”
**Sadhana**, vol. 42(7), pp. 1037-1050, July 2017.*(Co-authors were former students* - Amit Dutta, K.V.S. Hari, Chandra Murthy, Neelesh Mehta, Lajos Hanzo, ” Minimum Error Probability MIMO-Aided Relaying: Multi-Hop, Parallel and Cognitive Designs”,
**IEEE Transactions on Vehicular Technology**, vol.66(6), pp.5435-5440, June 2017.*(First author is a former student and other co-authors are collaborators)* - Rakshith Rajashekar, Naoki Ishikawa, Shinya Sugiura, K.V.S. Hari and L. Hanzo, “Full-Diversity Dispersion Matrices from Algebraic Field Extensions for Differential Spatial Modulation,”
**IEEE Transactions on Vehicular Technology**, vol. 66(1), pp. 385-394, Jan 2017.*(First author iss a former student and other co-authors are collaborators)* - Rakshith Rajashekar, K. V. S. Hari, Lajos Hanzo, “Transmit antenna subset selection for single and multiuser spatial modulation systems operating in frequency selective channels, accepted and to appear in
**IEEE Transactions on Vehicular Technology**.*(First author is a former student and third author is a collaborator)* - K. G. Deepa, Sooraj K. Ambat and K. V. S. Hari,”Fusion of sparse reconstruction algorithms for multiple measurement vectors,”
**Sadhana**, vol. 41(11), pp. 1275-1287, Nov. 2016.*(First and second authors were former students)* - Pranav S. Koundinya, K. V. S. Hari, Lajos Hanzo, “Joint Design of the Spatial and of the Classic Symbol Alphabet Improves Single-RF Spatial Modulation”,
**IEEE Access**vol. 4, pp. 10246-10257, Aug. 2016.*(First author was a project staff member and third author is a collaborator)* - Karthik Upadhya, Chandra Sekhar Seelamantula, K.V.S. Hari, “A Risk Minimization Framework for Channel Estimation in OFDM Systems”,
*accepted,***EURASIP Signal Processing**, vol. 128, pp. 78-87, Jan. 2016.*(First author was a project staff member and second author is a collaborator).* - Ping Yang, Yue Xiao, K.V.S. Hari, A. Chockalingam, Shinya Sugiura, Harald Haas, Marco Di Renzo, Zilong Liu, Lixia Xiao, Shaoqian Li, and Lajos Hanzo, “Single-Carrier Spatial Modulation for Large-Scale Antenna Aided Systems”
**IEEE Communications Surveys and Tutorials**, vol. 18(3), pp. 1687-1716, Mar. 2016.*(Authors are collaborators).* - Rakshith Rajashekar, K.V.S. Hari and Lajos Hanzo, “Quantifying the Transmit Diversity Order of Euclidean Distance Based Antenna Selection in Spatial Modulation”,
**IEEE Signal Processing Letters,**22 (9), pages 1434-1437, Sep 2015.*(First author is a PhD student and third author is a collaborator).* - Amit Dutta, K.V.S. Hari,and Lajos Hanzo, “Minimum-Error-Probability CFO Estimation for Muti-User MIMO OFDM Systems,”
**IEEE Transactions on Vehicular Technology**, 64 (7), pages 2804-2818, July 2015*(First author is a PhD student and third author is a collaborator).* - Sooraj K. Ambat and K.V.S. Hari, “An Iterative Framework for Sparse Signal Reconstruction Algorithms Signal Processing,”
**EURASIP Signal Processing (Elsevier),**vol. 108, pp. 351-364, Mar 2015.*(First author is a PhD student).* - Amit Dutta, K.V.S. Hari,and Lajos Hanzo, “Linear Transceiver Design for an Amplify-and-Forward Relay Based on the MBER Criterion,”
**IEEE Transactions on Communications**, vol. 62 (11), pages 3765-3777, Nov 2014.*(First author is a PhD student and third author is a collaborator).* - Dinesh Dileep Gaurav and K.V.S. Hari, “An Eigen Approach to Transmit Beamforming in Wireless Networks with Single Antenna Receivers,”
**IEEE Transactions on Wireless Communications**, vol. 13(11), pages 6431-6443, Nov 2014.*(First author is a PhD student).* - Mohammad Ismat Kadir, Sheng Chen, K.V.S. Hari, K. Giridhar and Lajos Hanzo, “Iterative Soft Multiple-Symbol Differential Sphere Decoding Aided Multicarrier Differential Space-Time Shift Keying,”
**IEEE Transactions on Vehicular Technology**, vol. 63 (8), pages 4102-4108, Oct 2014.*(Co-authors are collaborators*). - Sooraj K. Ambat, Saikat Chatterjee, K.V.S. Hari, “A Committee Machine Approach for Compressed Sensing Signal Reconstruction,”
**IEEE Transactions on Signal Processing,**vol. 62(7), pp.1705-1717, Apr 2014.*(First author is a PhD student and second author is a collaborator).* - Sooraj K. Ambat, Saikat Chatterjee, K.V.S. Hari, ” Progressive Fusion of Reconstruction Algorithms for Low Latency Applications in Compressed Sensing ”
**Signal Processing,**vol.97, pp. 146-151, Apr 2014.*(First author is a PhD student and second author is a collaborator).* - Renu Jose, Sooraj K. Ambat and K.V.S. Hari, “Low Complexity Joint Estimation of Synchronization Impairments in Sparse Channel for MIMO-OFDM System,”
**AEU – International Journal of Electronics and Communications, Elsevier Publications,**vol. 68(2), pp. 151-157,Feb 2014. (*First and second authors are PhD students).* - Rakshith Rajashekar, K.V.S. Hari, L. Hanzo, “Reduced-Complexity ML Detection and Optimal Training in Spatial Modulation Systems,”
**IEEE Transactions on Communications**, vol. 62(1), pp. 112-125, Jan 2014.*(First author is a PhD student and third author is a collaborator).* - Amit Datta, K.V.S. Hari, Lajos Hanzo “Channel Estimation Relying on the Minimum Bit Error Ratio Criterion for BPSK and QPSK Signals,”
**IET Communications**, vol. 8, pp.69-76, Jan 2014.*(First author is a PhD student and third author is a collaborator).* - Renu Jose, K.V.S. Hari, “A Bayesian Approach for Joint Estimation of Phase Noise and Channel in OFDM System,”
**IET Signal Processing**, vol.8 (1), pp. 10-20, Feb 2014.*(First author is a PhD student).* - N. Mukund Sriram, B.S. Adiga, K.V.S. Hari, ” Grassmannian Fusion Frames and its use in Block Sparse Recovery-”
**Signal Processing**, vol.94, pp. 498–502, Jan 2014. (*First author is a former student and second author is a collaborator).* - Rakshith Jagannath and K.V.S. Hari, “Block Sparse Estimator for Grid Matching in Single Snapshot DOA Estimation,”
**IEEE Signal Processing Letters,**vol. 20(11), pp.1038-1041, Nov 2013.*(First author was a project staff member).* - Dinesh Dileep Gaurav and K.V.S. Hari,” A Fast Eigen Solution for Homogeneous Quadratic Minimization with at most Three Constraints,”
**IEEE Signal Processing Letters,**vol. 20(10), pp.968-971, Oct 2013**.***(First author is a PhD student).* - Rakshith Rajashekar, Hari, K.V.S., Lajos Hanzo, “A Reduced-Complexity Partial-Interference-Cancellation Group Decoder for STBCs”
**IEEE Signal Processing Letters**, vol. 20(10), pp. 929-932, Oct 2013.*(First author is a PhD student and third author is a collaborator).* - K.V.S. Hari, John-Olof Nilsson, Isaac Skog, Peter Handel, Jouni Rantakokko, G.V. Prateek, “A Prototype of a First-Responder Indoor Localization System,”
**Special Issue on Cyber Physical Systems, Journal of IISc,**93(3), pp. 511-520, Sep 2013.*(Co-authors are collaborators*). - Renu Jose, K.V.S. Hari, “Maximum Likelihood Algorithms for Joint Estimation of Synchronization Impairments and Channel in MIMO-OFDM System,”
**IET Communications**, vol. 7(15), pp. 1567-1579, Aug 2013.*(First author is a PhD student).* - Rakshith Rajashekar, K.V.S. Hari, L. Hanzo, “Spatial Modulation aided Zero-Padded Single Carrier Transmission for Dispersive Channels,”
**IEEE Transactions on Communications**, vol. 61(6), pp. 2318-2329, June 2013.*(First author is a PhD student and third author is a collaborator).* - Sooraj K. Ambat, Saikat Chatterjee, K.V.S. Hari, Fusion of Algorithms for Compressed Sensing,”
**IEEE Transactions on Signal Processing**, vol.61 (14), pp. 3699-3704, 2013.*(First author is a PhD student and second author is a collaborator).* - Rong zhang, Li Wang, Gerard Parr, Osianoh Glenn Aliu, Benga Awoseyila, Nader Azarmi, Saleem Bhatti, Eliane Bodanese, Hong Chen, Mehrdad Dianati, Amit Dutta, Michael Fitch, K. Giridhar, Steve Hailes, K.V.S. Hari, Muhammad Ali Imran, Aditya K. Jagannatham, Abhay Karandikar, Santosh Kawade, Mohammed Zafar Ali Khan, Sayee C. Kompalli, Patrick Langdon, Babu Narayanan, Andreas Mauthe, Joseph Mc Geehan, Neelesh Mehta, Klutto Millet, Klaus Moessner, Rakshith Rajashekar, Barathram Ramkumar, Vinay Ribeiro, Kasturi Vasudevan, and Lajos Hanzo, ” Advances in base- and mobile-station aided cooperative wireless communications: An overview ”
**IEEE Vehicular Technology Magazine**, vol.8(1), pp. 57-69, March 2013.*(Co-authors are collaborators).* - Rakshith Rajashekar, Hari, K.V.S., Lajos Hanzo, “Antenna Selection in Spatial Modulation Systems”
**IEEE Communications Letters**vol. 17(3), pp. 521-524, Mar 2013.*(First author is a PhD student and third author is a collaborator).* - Rakshith Rajashekar, Hari, K.V.S., Lajos Hanzo, “Structured Dispersion Matrices from Division Algebra Codes for Space-Time Shift Keying,”
**IEEE Signal Processing Letters**vol. 20(4), pp. 371-374, Apr 2013.*(First author is a PhD student and third author is a collaborator).* - Avinash Mohan and K.V.S. Hari, “Low Complexity Adaptation for SISO Channel Shortening Equalizers,”
**AEU**–**International Journal of Electronics and Communications**, Elsevier Publications, 66(8), pp. 600–604, August 2012.*(First author was a project staff member).* - Satya Sudhakar Yedlapalli and K. V. S. Hari, ” The line Spectral Frequency Model of a Finite Length,” Special Issue on Model Order Selection in Signal Processing Systems,
**IEEE Journal of Selected Topics in Signal Processing**, vol. 4(3), pp.646-658, June 2010.*(First author was a PhD student).* - M R Bhavani Shankar and K V S Hari, ‘Systematic Construction of Linear Transform based Full Diversity, Rate One Space-Time-Frequency Codes,’
**IEEE Transactions on Signal Processing**, vol. 57, issue 6, pp. 2285-2298, June 2009.*(First author was a PhD student).* - M. R. Bhavani Shankar and K. V. S. Hari, ‘On the Variations in Mutual Information of MIMO Communication Systems Due to Perturbed Channel State Information at Transmitter’
**IEEE Transactions in Communications**, vol. 54(9), pp. 1593–1603, Sep 2006.*(First author was a PhD student).* - A. Vijaya Krishna and K. V. S. Hari ‘Filterbank Precoding for FIR equalization in high rate MIMO communications’
**IEEE Transactions on Signal Processing**, vol. 54 (5), pp. 1645 – 1652, May 2006.*(First author was a PhD student).* - M. R. Bhavani Shankar and K. V. S. Hari ‘Reduced Complexity Equalization schemes for Zero Padded OFDM Systems,’
**IEEE Signal Processing Letters**, Volume: 11(9), pp. 752- 755, Sep 2004.*(First author was a PhD student).* - V. G. S. Prasad and K. V. S. Hari, ‘Interleaved Orthogonal Frequency Division Multiplexing (IOFDM) System,’
**IEEE Transactions on Signal Processing**, vol. 52(6), pp. 1711-1721, June 2004.*(First author was an ME student).* - H. Bolcskei, A. J. Paulraj, K. V. S. Hari, R. U. Nabar, W. W. Lu, ‘Fixed broadband wireless access: state of the art, challenges, and future directions,’
**IEEE Communications Magazine**pp. 100 -108, Jan 2001.*(Co-authors were collaborators).* - G. Ganesan and K. V. S. Hari, `HOS based orthogonal subspace algorithms for causal ARMA system identification,’
**EURASIP’s Signal Processing**, vol. 80, Issue 3, pp. 535-542, March 2000.*(First author was a Master’s student).* - K. V. S. Hari and B. V. Ramakrishnan, `Performance analysis of a modified spatial smoothing technique for direction estimation,’
**EURASIP’s Signal Processing**, vol. 79, Issue 1, pp. 73-85, November 1999.*(First author was a Master’s student).* - K. V. S. Hari and Bjorn Ottersten, `Parameter Estimation using a Sensor Array in a Ricean Fading channel,’
**Sadhana, Proceedings of Indian Academy of Sciences in Engineering Sciences**‘ vol. 23, Part I, pp. 5-15, February 1998. - Sachin S. Deo and K. V. S. Hari,`Simple method to compute a function in fixed-point arithmetic,’
**Electronics Letters**, vol.33, no. 23, pp. 1631-1632, November 1997.*(First author was a Master’s student).* - L.Srinivas and K. V. S. Hari,`FIR System Identification based on Subspaces of a Higher-Order Cumulant Matrix,’
**IEEE Transactions on Signal Processing**, vol. 46, June 1996.*(First author was a Master’s student).* - L.Srinivas and K. V. S. Hari,`FIR System Identification using Higher-Order Cumulants – A Generalized Approach,’
**IEEE Transactions on Signal Processing**, December 1995.*(First author was a Master’s student).* - K. V. S. Hari and Uma Gummadavelli, `Effect of Spatial Smoothing on the performance of Subspace methods in the presence of Array Model Errors,’
**Special Issue on Statistical Signal Processing and Control, IFAC Journal, Automatica**, January 1994.*(Second author was a Master’s student).* - Bhaskar D. Rao and K. V. S. Hari, `Weighted Subspace Methods and Spatial Smoothing: Analysis and Comparison,’
**IEEE Transactions on Signal Processing**, Vol. 41, No. 2, pp 788-803, February 1993. - Bhaskar D. Rao and K. V. S. Hari,`Analysis of Subspace based DOA Estimation Methods,’
**Sadhana, Proceesings of Indian Academy of Sciences in Engineering Sciences’ Special Issue on Recent advances in Digital Signal Processing**, vol. 16, Part 3, pp. 183-194, November 1991. - Bhaskar D. Rao and K. V. S. Hari, `Effect of Spatial Smoothing on the Performance of MUSIC and the Minimum-Norm method,’
**Proceedings of IEE,**Vol. 137, Part F, No. 6, pp 449-458, December 1990. - Bhaskar D. Rao and K. V. S. Hari, `Performance Analysis of Root-Music,’
**IEEE Transactions on Acoustics, Speech and Signal Processing**, Vol. 43, pp 1939-1949, December 1989. - Bhaskar D. Rao and K. V. S. Hari, `Performance Analysis of ESPRIT and TAM in determining the Direction of Arrival of Plane Waves in Noise,’
**IEEE Transactions on Acoustics, Speech and Signal Processing**, Vol. 37, pp 1990-1994, December 1989. - Bhaskar D. Rao and K. V. S. Hari, `Statistical Performance Analysis of the Minimum-Norm method,’
**Proceedings of IEE**, Vol. 136, Part F, no. 3, pp 125-134, June 1989. - Surendra Prasad and K.V.S.Hari, `Adaptive Seismic Deconvolution via the Canonical Variate Analysis,’
**Journal of IETE**, vol. 34, no. 5, pp. 423-430, September-October 1988. - Surendra Prasad and K. V. S. Hari, `Improved ARMA Spectral Estimation using the Canonical Variate Method,’
**IEEE Transactions on Acoustics, Speech and Signal Processing,**Vol. 35, pp 900-903, June 1987.

**BOOK CHAPTERS**

- Y Agrawal, A Kushwaha, GK Ananthasuresh, KVS Hari, S Khandai, “An Assistive Chair using a Series-Elastic Actuator,” 4th International and 19th National Conference on Machines and Mechanisms
- K Gunde, KVS Hari, “Modified Generalised Quadrature Spatial Modulation.” 2019 National Conference on Communications (NCC), 1-5.
- K. V. S. Hari, ‘Channel Models for Wireless Communication Systems,’ Wireless Network Design Optimization Models and Solution Procedures by Kennington, Jeff; Olinick, Eli; Rajan, Dinesh (Eds.), International Series in Operations Research & Management Science, Springer-Verlag, Vol. 158, 1st Edition, 2011.
- Joby Joseph and K. V. S. Hari,’Direction Estimation of Broadband sources for Auditory Localization and Spatially Selective Listening,’Advances in Direction-of-Arrival Estimation (Artech House Radar Library), S. Chandran, editor, Artech House , December 2005.
- K. V. S. Hari and V. G. S. Prasad, ‘Space-Time and Space-Frequency Block Coded Interleaved OFDM System,’ Adaptive Antenna Arrays, S. Chandran, Editor, Springer Verlag, Berlin, June 2004.
- Bhaskar D. Rao and K.V.S.Hari,`Spatial Smoothing and MUSIC: Further Results,’ SVD and Signal Processing , II Algorithms, Analysis and Applications, R. J. Vaccaro, Editor, Elsevier Science Publishers, B.V., Amsterdam, 1991.

**PATENTS**

- Satya Sudhakar Yedlapalli, K.V.S. Hari, “Determining spectral samples of a finite length sequence at non-uniformly spaced frequencies,”
**US patent 8594167****granted on 26 Nov 2013.** - Satya Sudhakar Yedlapalli, K.V.S. Hari, “Filtering Discrete-time signals using Notch Filters”
**USPTO Patent # 9112479, Aug 2015** - Satya Sudhakar Yedlapalli and K.V.S. Hari, “Determining spectral samples of a finite length sequence at non-uniformly spaced frequencies,”
**Japanese Patent # IN-800641-04-JP-NAT**, May 2015. - Satya Sudhakar Yedlapalli and K.V.S. Hari, “Determining spectral samples of a finite length sequence at non-uniformly spaced frequencies,”
**Korean Patent # IN-800641-04-KR-NAT**, Mar 2015. - Satya Sudhakar Yedlapalli and K. V. S. Hari , “Filtering Discrete-Time Signals Using a Notch Filter,”
**PCT publication # WO/2012/052807**, 2012. - Satya Sudhakar Yedlapalli and K. V. S. Hari , “Filtering Discrete-Time Signals Using a Notch Filter,”
*Indian patent priority # 03081/CHE/2010*, 2010. - V.G.S. Prasad, K.V.S. Hari, “INTERLEAVED ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (IOFDM) SYSTEM,”
**Indian Patent 198687**, May 2006.

**CONFERENCE PAPERS**

- CG Jansson, R Thottappillil, S Hillman, S Möller, KVS Hari, R Sundaresan, “Experiments in Creating Online Course Content for Signal Processing Education,” Proc. of 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (
**ICASSP 2020**), Barcelona, May 2020. - Shubham Sharma, K.V.S. Hari and Geert Leus, “Space Filling Curves for MRI Sampling,” Proc. of 2020 IEEE International Conference on Acoustics, Speech and Signal Processing, Barcelona (
**ICASSP 2020**), May 2020 - Shubham Sharma, K.V.S. Hari and Geert Leus, “K-Space Trajectory Design for Reduced MRI Scan Time,” Proceedings of 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (
**ICASSP 2020**), Barcelona, May 2020. - Y Agrawal, A Kushwaha, GK Ananthasuresh, KVS Hari, S Khandai,”An Assistive Chair using a Series-Elastic Actuator,” 4 th International and 19th
**National Conference on Machines and Mechanism**, Dec 2019 - A Agrawal, S Nag, KVS Hari, SP Arun, “Upright bigram processing predicts reading fluency,”Sixth Annual Conference of the Association for Cognitive Science,
**ACCS 2019** - Kiran Gunde, K.V.S. Hari, ” Modified Generalised Quadrature Spatial Modulation,” Proc. of National Conference on Communications,
**NCC2019**, Bangalore, Feb 2019. - Aakash Agarwal, K.V.S. Hari, S.P. Arun, “How does reading expertise influence letter representations in the brain? An fMRI study,”
**Vision Sciences Society**Annual Meeting, Florida, May 2018. - G. S. Muralikrishna, Sooraj K. Ambat, K.V.S. Hari, ” Batch Look Ahead Orthogonal Matching Pursuit,” Prof. of
**National Conference on Communications,****NCC 2018**, Hyderabad, Feb 2018. - Aakash Agarwal, K.V.S. Hari, S.P. Arun, “How reading changes letter representations: a double dissociation using orthographically distinct scripts in India,”
**Vision Sciences Society**Annual Meeting, Florida, May 2017. - Deepa K. G., Sooraj K. Ambat, K. V. S. Hari, “Fusion of Algorithms for Multiple Measurement Vectors,” Proc. of 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (
**ICASSP 2016**), Shanghai, March 2016. - Sooraj K. Ambat, Shree Ranga Raju N.M. and K.V.S. Hari, “Gini Index based Search Space Selection in Compressive Sampling Matching Pursuit,” IEEE
**INDICON 2014**, 11-13 Dec 2014, Pune, India. - Girisha R. Shetty and K.V.S. Hari and Peter Handel, “Fusing the Navigation Information of Dual Foot-Mounted Zero-Velocity-Update-Aided Inertial Navigation Systems,” International Conference on Signal Processing and Communications,
**SPCOM 2014**, July 2014, Bangalore, India. - Prateek Basavapur Swamy, Sooraj K. Ambat, Saikat Chatterjee, K.V.S. Hari, “Reduced Look Ahead Orthogonal Matching Pursuit”, published
**National Conference on Communications, NCC 2014**, Feb 2014, Kanpur, India. - Deepa K G, Sooraj K. Ambat, K.V.S. Hari, “Modified Greedy Pursuits for Improving Sparse Recovery”,
**National Conference on Communications, NCC 2014**, Feb 2014, Kanpur, India. - J-O. Nilsson, I. Skog, P. Händel, M. Olsson, J. Rantakokko, K.V.S. Hari, “Accurate Indoor Positioning of Firefighters Using Dual Foot-mounted Inertial Sensors and Inter-agent Ranging”, published
**IEEE/ION Position Location and Navigation Symposium,**May 2014. - Rakshith Rajashekar, K.V.S. Hari, K. Giridhar, L. Hanzo, “Performance Analysis of Antenna Selection Algorithms in Spatial Modulation Systems with Imperfect CSIR”,
**European Wireless 2013**, Guildford, UK, 16-18 Apr. 2013. - Sooraj K. Ambat, Saikat Chatterjee, K.V.S. Hari, “Fusion of Algorithms for Compressed Sensing”, publication in
**ICASSP 2013**, Vancouver, Canada, 29-31 May 2013. - G. V. Prateek, Girisha R. Shetty, K.V.S. Hari, Peter Handel,”Data Fusion of Dual Foot-Mounted INS to Reduce the Systematic Heading Drift,” Proceedings of 4th International Conference on Intelligent Systems, Modelling and Simulation (ISMS 2013), 29-31 Jan 2013, Bangkok, Thailand.
- G. V. Prateek, Nijil K., K.V.S. Hari,” Classification of Vehicles Using Magnetic Field Angle Model,” Proceedings of 4th International Conference on Intelligent Systems, Modelling and Simulation (ISMS 2013), 29-31 Jan 2013, Bangkok, Thailand.
- Prateek G. V., Rajkumar V. , Nijil K. , and K.V.S. Hari; , “Classification of Vehicles Using Magnetic Dipole Model,” Proceedings of
**IEEE TENCON 2012**, 19-22 Nov 2012, Cebu, Philippines. - Rakshith Rajashekar and K.V.S. Hari, “Modulation Diversity for Spatial Modulation Using Complex Interleaved Orthogonal Design,” Proceedings of
**IEEE TENCON 2012**, 19-22 Nov 2012, Cebu, Phillipines. - Sooraj K. Ambat, Saikat Chatterjee, and K.V.S. Hari “Subspace Pursuit Embedded in Orthogonal Matching Pursuit,” Proceedings of
**IEEE TENCON 2012**, 19-22 Nov 2012, Cebu, Philippines. - Sooraj K. Ambat, Saikat Chatterjee, and K.V.S. Hari “On Selection of Search Space Dimension in Compressive Sampling Matching Pursuit,” Proceedings of
**IEEE TENCON 2012**, 19-22 Nov 2012, Cebu, Philippines. - Sooraj K Ambat, Saikat Chatterjee, K.V.S. Hari, “Fusion of Matching Pursuits for Compressed Sensing Signal Reconstruction”,
**EUSIPCO 2012**, European Signal Processing Conference, 27-31 Aug. 2012, Bucharest, Romania. - Yashwanth M, K.V.S. Hari, “Delay Optimized Zero-Forcing Channel Shortening Algorithm for Wireless Communication,” Proceedings of International Conference on Signal Processing and Communication (
**SPCOM 2012**), July 2012, Bangalore, India. - Li Wang, K.V.S. Hari and Lajos Hanzo,”Iterative Amplitude/Phase Multiple-Symbol Differential Sphere Detection for DAPSK Modulated Transmissions,” Proceedings of IEEE International Conference on Communications(
**ICC 2012**), 10-15 Jun 2012, Ottawa, Canada. - J-O. Nilsson, I. Skog, P. Handel and K.V.S. Hari,”Foot-Mounted INS for Everybody — An Open-Source Embedded Implementation,” Proceedings of IEEE/ION Position Location and Navigation System (
**PLANS**) Conference, 24-26 April 2012, Myrtle Beach, South Carolina, USA. - N. Mukund Sriram, B.S. Adiga and K.V.S. Hari,”Burst Error Correction using Partial Fourier Matrices and Block Sparse Representation,” Proceedings of National Conference on Communications (
**NCC 2012**), 3-5 Feb 2012, IIT Kharagpur, India. - Renu Jose and K.V.S. Hari, “Joint Estimation of Synchronization Impairments in MIMO-OFDM System,” Proceedings of National Conference on Communications (
**NCC 2012**), 3-5 Feb 2012, IIT Kharagpur, India. - Sooraj K. Ambat, Saikat Chatterjee, K.V.S. Hari,”Adaptive Selection of Search Space in Look Ahead Orthogonal Matching Pursuit,”Proceedings of National Conference on Communications (
**NCC 2012**), 3-5 Feb 2012, IIT Kharagpur, India. - Saikat Chatterjee, K.V.S. Hari, Peter Handel and Mikael Skoglund,”Projection-Based Atom Selection in Orthogonal Matching Pursuit for Compressive Sensing,” Proceedings of National Conference on Communications (
**NCC 2012**), 3-5 Feb 2012, IIT Kharagpur, India. - M. R. Rakshith, K. V. S. Hari, Lajos Hanzo, “Field Extension Code Based Dispersion Matrices for Coherently Detected Space-Time Shift Keying,” Proceedings of IEEE Globecom 2011, 5-9 Dec 2011, Houston, USA.
- Dinesh Dileep Gaurav and K. V. S. Hari, “Degrees of Freedom of Relay aided MIMO X network with Orthogonal Components,” Proceedings of the 14th International Symposium on Wireless Personal Multimedia Communications (
**WPMC**2011), Oct 2011, Brest, France. - Avinash Mohan and KVS Hari, “Low Complexity Adaptation for Channel Shortening Equalizers,” Proceedings of 54th IEEE International Midwest Symposium on Circuits and Systems (
**IEEE MWSCAS**2011), Aug7-10 2011, Seoul, S. Korea. - K. V. S. Hari and V. Lalitha, “SUBSPACE-BASED DOA ESTIMATION USING FRACTIONAL LOWER ORDER STATISTICS,” Proceedings of IEEE International Conference on Acoustics Speech and Signal Processing (
**ICASSP**2011), May 22-27 2011, Prague, Czech Republic. - Amit K Datta and K. V. S. Hari, “Channel Estimation Using Minimum Bit Error Rate Framework for BPSK Signals ” Proceedings of IEEE Vehicular Technology Conference (
**VTC**-Spring), May 15-18 2011, Budapest, Hungary. - K. V. S. Hari, Rakshith Jagannath, Satya Sudhakar Yedlapalli, “Sensitivity Analysis of Minimum-Phase FIR Filters based on the Line Spectral Frequency Model”, Proceedings of
**APSIPA**Annual Summit and Conference 2010, 14-17 Dec 2010, Singapore. (available online at http://www.apsipa.org/proceedings.htm ) - Avik Santra and K V S Hari, “Novel Subspace methods for Blind Estimation of Multiple CFOs in MIMO-OFDM Systems,” Proceedings of International Conference on Signal Processing (
**ICSP**2010) conference, Beijing, October 2010. - Avik Santra and K V S Hari, “Low Complexity PARAFAC Receiver for MIMO-OFDMA System in the Presence of Multi-Access Interference,” Proceedings of 44th
**Asilomar**Conference on Signals, Systems and Computers, Pacific Grove, CA, USA November 2010. - G V S S K R Naganjaneyulu and K V S Hari, “Study Of Acoustic Source Localization Algorithm For Planar arrays” Proceedings of IEEE International Conference,
**TENCON**2010, Fukuoka, Japan, November 2010. - M R Bhavani Shankar and K V S Hari, “On the Diversity and Complexity of Zero Forcing Receivers for MIMO Zero Padded Systems,” Proceedings of International Conference on Signal Processing and Communication (
**SPCOM**2010), Bangalore July 2010. - Nithya V S, Karthik Sheshadri, Anurag Kumar, K V S Hari, “Model-Based Target Tracking in a Wireless Network of Passive Infrared Sensor Nodes,” Proceedings of International Conference on Signal Processing and Communication (
**SPCOM**2010), Bangalore July 2010. - Satya Sudhakar Yedlapalli and K V S Hari,”A Novel Property of an Auto-Correlation Sequence and some Applications,” Proceedings of International Conference on Signal Processing and Communication (
**SPCOM**2010), Bangalore July 2010. - A Vijayakrishna and K V S Hari, “Jointly Optimal MMSE Design for Non-redundant FIR Precoding and Equalization,” to appear in the Proceedings of International Conference on Signal Processing and Communication (
**SPCOM**2010), Bangalore July 2010. Will be available at IEEE Xplore. - Satya Sudhakar Yedlapalli and K. V. S. Hari, “The Canonic Linear-Phase FIR lattice Filter Structures,” Proceedings of National Conference on Communications (
**NCC**-2010), Jan 2010. - Muralidhar, Karthik Li, Kwok H. K V S Hari , ” Iterative Kalman-AR Method for Doppler Spread Estimation in Flat Fading Channels ” IEEE Conference on Personal, Indoor and Mobile Radio Communications, 2007(
**PIMRC**2007) 3-7 sept. 2007,page(s): 1-5. - R. Deepak and K. V. S. Hari,’ Harmonic mean of squared product distances: a new criterion to design codes for independent fading channels,’ Proceedings of 2004 International Conference on Signal Processing and Communications (
**SPCOM**2004),} Bangalore, Dec 2004. - A. Vijaya Krishna and K. V. S. Hari,’Minimum redundancy for FIR equalization in MIMO multicarrier modulation,’ Proceedings of 2004 International Conference on Signal Processing and Communications (
**SPCOM**2004),} Bangalore, Dec 2004. - Avinash Achar and K. V. S. Hari,’Parametric Localization of Correlated Incoherently Distributed Sources Using ESPRIT,’ Proceedings of IEEE Sensor Array and Multichannel Signal Processing Workshop,
**SAM**2004,Barcelona, July 2004. - Vijayakrishna A. and K. V. S. Hari,’Filterbank precoding for MIMO frequency selective channels: Minimum redundancy and equalizer design,’ Proceedings of IEEE Sensor Array and Multichannel Signal Processing Workshop,
**SAM**2004, Barcelona, July 2004. - Vinod T.S and K. V. S. Hari,’Optimal Pilot tones for MIMO Interleaved OFDM systems,’ Proceedings of
**ICASSP**2004, Montreal, May 2004. - Karthik S. and K. V. S. Hari, ‘Alternative Interleaving schemes for Interleaved Orthogonal Frequency Division Multiplexing,’ Proceedings of
**TENCON**2003 – 2003 IEEE Region 10 Conference on Convergent Technologies for the Asia-Pacific, Bangalore, Oct 2003. - Joby Joseph and K. V. S. Hari, ‘Adaptive estimation of parameters using partial information of desired outputs,’ Proceedings of
**TENCON**2003 – 2003 IEEE Region 10 Conference on Convergent Technologies for the Asia-Pacific, Bangalore, Oct 2003. - M. R. Bhavani Shankar and K. V. S. Hari, ‘Bounds on MIMO capacity due to channel perturbations,’ in Proc of
**NCC**2003, Chennai, Jan 2003. - V. G. S. Prasad and K. V. S. Hari, ‘Interleaved Orthogonal Frequency Division Multiplexing (IOFDM)System with lesser complexity ‘ Proc of
**NCC**2003, Chennai, Jan 2003. - M. R. Bhavani Shankar and K. V. S. Hari, ‘On the Variations in Capacity of MIMO Communication Systems to Channel Perturbations,’ Proc of
**ICPWC**2002, New Delhi, Dec 2002. - V. G. S. Prasad and K. V. S. Hari, ‘Space-Time Block Coded Interleaved Orthogonal Frequency Division Multiplexing System ‘ Proc. of
**ICPWC**2002, New Delhi, Dec 2002. - V. G. S. Prasad and K. V. S. Hari, ‘Interleaved Orthogonal Frequency Division Multiplexing System ‘ Proc. of
**ICASSP 2002**, Orlando, May 2002. - Joby Joseph and K. V. S. Hari, ‘An algorithm to estimate multipath delays of broadband sources with only two sensors’, Tenth Annual IEEE Symposium on Multimedia Communications and Signal Processing, Bangalore, Nov 2001.
- D. S. Baum, R. Nabar, S. Panchanathan, K. V. S. Hari, V. Erceg, A. Paulraj, `Measurements and Characterization of Broadband MIMO Fixed Wireless Channels at 2.5 GHz,’ Proc of IEEE Intl. Conf. on Personal Wireless Communication (
**ICPWC**2000), Hyderabad, India, Dec 2000. - G. Cirrincione, G. Ganesan, K.V.S.Hari and S. Van Huffel, ‘Direct and neural techniques for the data least squares problem’ Proceedings of Mathematical Theory of Networks and Systems, Perpignan, France, June 19-23, 2000.
- Anurag Kumar, K. V. S. Hari, R. Shobhanjali and Srikumar Sharma, `Long-Range Dependence in the Aggregate Flow of TCP controlled Elastic sessions: An Investigation via the Processor Sharing Model,’ Proceedings of the National Conference on Communications,
**NCC**, Jan 2000. - Shishir K. L., K. V. S. Hari and Risto Wichman, `Low complexity method to estimate Co-channel signals using an Antenna Array,’ Proceedings of the IEEE International Conference on Personal Wireless Communications (
**ICPWC**’99), Jaipur, Feb 1999. pdf file - Shishir K. L. and K. V. S. Hari, `Detection of the number of Constant Modulus sources arriving at an antenna array,’ Proceedings of the IEEE International Symposium on Wireless Communications for the Next Millennium, New Delhi, Sept 1998.
- Raghuraman M. and K. V. S. Hari, `Estimation of nominal AOA and angular spread for spatially distributed sources in Ricean fading channels,’ Proceedings of the IEEE International Symposium on Wireless Communications for the Next Millennium, New Delhi, Sept 1998.
- K. V. S. Hari and Bjorn Ottersten, `Parameter Estimation using a Sensor Array in a Ricean Fading channel,’ Proceedings of
**SPCOM**’97, Bangalore, July 1997. - Y. Lavanis and K. V. S. Hari, `A Kernel for Wigner Distribution using Wigner Synthesis Techniques,’ Proceedings of the Workshop on Underwater Systems and Engineering, Visakhapatnam, August 1994.
- L. Srinivas and K. V. S. Hari, FIR System Identification using Higher Order Cumulants,’ Proceedings of the National Symposium of Systems, pp. 201-205, Madras, October 1993.
- K. V. S. Hari and Uma Gummadavelli, `On the Performance of Subspace methods in the presence of Array Model Errors and Spatial Smoothing,’ Proceedings of
**ICASSP**, Minnesota, April 1993. pdf file - Bhaskar D. Rao and K.V.S.Hari, `Weighted State Space Methods/ESPRIT and Spatial Smoothing’ Proceedings of ICASSP, Toronto, Canada, April 1991.
- Bhaskar D. Rao and K.V.S.Hari,`On Spatial Smoothing and Weighted Subspace Methods’ Proceedings of 24th Asilomar Conference on Signals, Systems and Computers, Monterey, Nov 90.
- Bhaskar D. Rao and K.V.S.Hari,`Effect of Spatial Smoothing on State Space Methods/ESPRIT,’ Proceedings of 5th ASSP Workshop on Spectrum Estimation and Modelling, October 1990.
- Bhaskar D. Rao and K.V.S.Hari,`Effect of Spatial Smoothing on the Performance of Noise Subspace Methods,’ Proceedings of ICASSP, Albuquerque, New Mexico, April 1990.
- Bhaskar D. Rao and K.V.S.Hari,`MUSIC and Spatial Smoothing: A Statistical Performance Analysis,’ Proceedings of 23rd Asilomar Conference on Signals, Systems and Computers, Monterey, Nov 89.
- Bhaskar D. Rao and K.V.S.Hari,`Statistical Performance Analysis of the Minimum-Norm method,’ Proceedings of ICASSP, Glasgow, Scotland, May 1989.
- Bhaskar D. Rao and K.V.S.Hari,`Performance Analysis of Root-Music,’ Proceedings of 22nd Asilomar Conference on Signals, Systems and Computers, Monterey, November 1988.
- Bhaskar D. Rao and K.V.S.Hari,`Performance Analysis of Subspace-based methods,’ Proceedings of 4th ASSP Workshop on Spectrum Estimation and Modelling, Minnesota, August 1988.