Research and research interests

My research area is quantum Information Theory as well as classical Information Theory in the spirit of C.E. Shannon. The current topics of interest in both fields include coding theorems for systems with channel uncertainty such as compound and arbitrarily varying channels. Recently we have started some research on secrecy/privacy aspects of such channel models.

We are also working on other basic protocols of quantum Information Theory, e.g. quantum state merging, which together with the theory of quantum channel coding are building blocks of Quantum Shannon Theory.   

My not-so-recent work includes ergodic theorems for quantum entropies of ergodic states on quasi-local algebras or lattice systems and large deviations  results a la Sanov for  this type of operator algebras.

Publications

Preprints

• Quantum Stein's lemma revisited, inequalities for quantum entropies, and a concavity theorem of Lieb, I. Bjelakovic and Ra. Siegmund-Schultze (2012)

 Journal Papers

• Universal quantum state merging, I. Bjelakovic, H. Boche, and G. Janßen, submitted (2012)
• Secrecy results for compound wiretap channels, I. Bjelakovic, H. Boche, and J. Sommerfeld, submitted (2011)
• Quantum Capacity under adversarial quantum noise: arbitrarily varying quantum channels R. Ahlswede, I.Bjelakovic, H. Boche, and J. Nötzel, submitted to Communications in Mathematical Physics
• The Compound Multiple Access Channel with Partially Cooperating Encoders M. Wiese, H. Boche, I. Bjelakovic, and V. Jungnickel, IEEE Transactions on Information Theory, Vol. 57, No. 5, pp. 3045-3066 (2011), Special Issue on Interference Networks
• Optimal Coding Strategies for Bidirectional Broadcast Channels Under Channel Uncertainty R. F. Wyrembelski, I. Bjelakovic, T. J. Oechtering, and H. Boche, IEEE Transactions on Communications, vol. 58, no. 10, pp. 2984-2994, Oct. 2010.
• Classical Capacities of Compound and Averaged Quantum Channel I.Bjelakovic and H. Boche, IEEE Transactions on Information Theory, vol. 55, no. 7, pp. 3360-3374, July 2009
• Entanglement transmission and generation under channel uncertainty:Universal quantum channel coding  I. Bjelakovic, H. Boche, and J. Nötzel, Communications in Mathematical Physics 292, pp. 55-97, 2009
• Quantum Capacity of a Class of Compound Channels  I. Bjelakovic, H. Boche, and J. Nötzel, Physical Review A, vol. 78, p. 042331, 2008
• Typical support and Sanov large deviations of correlated states I.Bjelakovic, J. Deuschel, T. Krueger, R. Seiler, R. Siegmund-Schultze, and A. Szkola, Communications in Mathematical Physics, vol. 297, pp. 559-584, 2008
• Ergodic Classical-Quantum Channels: Structure and Coding Theorems    I. Bjelakovic and H. Boche, IEEE Transactions on Information Theory, vol. 54, no. 2, pp. 723-742, Feb. 2008
• Broadcast Capacity Region of Two-Phase Bidirectional Relaying  T. J. Oechtering, C. Schnurr, I. Bjelakovic, and H. Boche, IEEE Transactions on Information Theory, vol. 54, no. 1, pp. 454-458, Jan. 2008.
• A quantum version of Sanov's theorem I. Bjelakovic, J. Deuschel, T. Krüger, R. Seiler, R. Siegmund-Schultze, and A. Szkola, Communications in Mathematical Physics, vol. 260, no. 3, pp. 659-671, Dec. 2005.
• The data compression theorem for ergodic quantum information sources I. Bjelakovic and A. Szkola, Quantum Information Processing, vol. 4, no. 1, pp. 49-63, Feb. 2005.
• The Shannon-Mcmillan theorem for ergodic quantum lattice systems I. Bjelakovic, T. Krüger, R. Siegmund-Schultze, and A. Szkola, Inventiones Mathematicae, vol. 155, pp. 203-222, 2004
• An ergodic theorem for the quantum relative entropy I. Bjelakovic and R. Siegmund-Schultze, Communications in Mathematical Physics, vol. 247, pp. 697-712, 2004

Conference, Symposium, and Workshop Papers      

• Capacity results for compound wiretap channels, I. Bjelakovic, H. Boche, and J. Sommerfeld, Proc. Information Theory Workshop (ITW 11), Paraty, Brazil, Oct. 2011
• Universal Quantum State Merging, I. Bjelaković, H. Boche, and G. Janßen, Proc. IEEE International Symposium on Information Theory (ISIT '11), Saint Petersburg, Russia, Aug. 2011, pp. 21-25.     
• The Compound MAC With Common Message and Partial Channel State Information
  M. Wiese, H. Boche, and I. Bjelakovic, Proc. International Symposium on Information Theory and its Applications (ISITA 2010), Taichung, Taiwan, October 2010.
• Bidirectional Relaying in Wireless Networks - Impact of Degree of Coordination R. F. Wyrembelski, I. Bjelakovic, and H. Boche, Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP '10), Dallas, Texas, USA, Mar. 2010, pp. 3234-3237.
• Entanglement Transmission over Arbitrarily Varying Quantum Channels R. Ahlswede, I. Bjelakovic, H. Boche, and J. Nötzel, Proc. IEEE Internationsl Symposium on Information Theory (ISIT 2010) Austin, Texas, June 2010, Available at arXiv.org.
• Downlink With Partially Cooperating Base Stations M. Wiese, H. Boche, I. Bjelakovic, and V. Jungnickel, Proc. The 11th IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2010), Marrakech, Morocco, June 2010.
• On Arbitrarily Varying Bidirectional Broadcast Channels with Constraints on Input and States R. F. Wyrembelski, I. Bjelakovic, and H. Boche, Proc. IEEE International Symposium on Information Theory and its Applications (ISITA '10), Taichung, Taiwan, Oct. 2010, pp. 410-415.
• List Decoding for Bidirectional Broadcast Channels with Unknown Varying Channels R. F. Wyrembelski, I. Bjelakovic, and H. Boche, Proc. IEEE International Conference on Communications (ICC '10), Cape Town, South Africa, May 2010, pp. 1-6.
• On the Capacity of Bidirectional Relaying with Unknown Varying Channels R. F. Wyrembelski, I. Bjelakovic, and H. Boche, Proc. IEEE Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP '09), Aruba, Dutch Antilles, Dec. 2009, pp. 269-272.
• Entanglement Transmission Capacity of Compound Channels I. Bjelakovic, H. Boche, and J. Nötzel, Proc. of International Syposium on Information Theory ISIT 2009, Seoul, Korea, July 2009, preprint available at www.arxiv.org.
• Coding Strategies for Bidirectional Relaying for Arbitrarily Varying Channels R. F. Wyrembelski, I. Bjelakovic, and H. Boche, Proc. IEEE Global Communications Conference (GLOBECOM '09), Honolulu, Hawaii, USA, Dec. 2009, pp. 1-6.
• On the Capacity of Bidirectional Broadcast Channels under Channel Uncertainty R. F. Wyrembelski, I. Bjelakovic, T. J. Oechtering, and H. Boche, Proc. IEEE International Conference on Communications (ICC '09), Dresden, Germany, June 2009, pp. 1-5.
• Capacity of Gaussian MIMO Bidirectional Broadcast Channels R. F. Wyrembelski, T. J. Oechtering, I. Bjelakovic, C. Schnurr, and H. Boche, Proc. IEEE International Symposium on Information Theory (ISIT '08), Toronto, Canada, July 2008, pp. 584-588.
• On the Boundedness of the Support of Optimal Input Measures for Rayleigh Fading Channels J. Sommerfeld, I. Bjelakovic, and H. Boche, Proc. IEEE International Symposium on Information Theory (ISIT 2008) Toronto, Canada, July 2008.
• Classical Capacity of Averaged Quantum Channels I. Bjelakovic and H. Boche, Proc. IEEE International Symposium on Information Theory (ISIT 2008) Toronto, Canada, July 2008.
• Classical Capacities of Compound Quantum Channels I. Bjelakovic and H. Boche, Proc. IEEE Information Theory Workshop (ITW 2008) Porto, Portugal, May 2008.
• Achievable Rate Region of a Two Phase Bidirectional Relay Channel T. J. Oechtering, C. Schnurr, I. Bjelakovic, and H. Boche, Proceedings of the 41st Annual Conference on Information Sciences and Systems, Mar. 2007.
• On the Strong Converse for the Broadcast Capacity Region of Two-Phase Bidirectional Relaying I. Bjelakovic, T. J. Oechtering, C. Schnurr, and H. Boche, Proc. IEEE Information Theory Workshop (ITW '07), Bergen, Norway, July 2007.
• Structure of Optimal Input Covariance Matrices for MIMO Systems with Covariance Feedback under General Correlated Fading I. Bjelakovic and H. Boche, Proc. IEEE International Symposium on Information Theory (ISIT 2006) Seattle WA, USA, July 2006.
• Limit Theorems for Quantum Entropies and Applications I. Bjelakovic, Proc. 6th International ITG Conference on Source and Channel Coding, Munich, Germany, Apr. 2006.

Unpublished

• A New Proof of the Monotonicity of Quantum Relative Entropy for Finite Dimensional Systems I. Bjelakovic and R. Siegmund-Schultze, 2003, Not intended for publication.
• Chained typical subspaces-A quantum version of Breiman's theorem I. Bjelakovic, T. Krueger, R. Siegmund-Schultze, and A. Szkola, 2003, SFB 288 preprint Nr. 581. .

arXiv preprints

Most of the papers listed above and some that are not submitted yet can be found at arXiv