{"oa_version":"None","abstract":[{"lang":"eng","text":"We consider the problem of communication over adversarial channels with feedback. Two parties comprising sender Alice and receiver Bob seek to communicate reliably. An adversary James observes Alice's channel transmission entirely and chooses, maliciously, its additive channel input or jamming state thereby corrupting Bob's observation. Bob can communicate over a one-way reverse link with Alice; we assume that transmissions over this feedback link cannot be corrupted by James. Our goal in this work is to study the optimum throughput or capacity over such channels with feedback. We first present results for the quadratically-constrained additive channel where communication is known to be impossible when the noise-to-signal (power) ratio (NSR) is at least 1. We present a novel achievability scheme to establish that positive rate communication is possible even when the NSR is as high as 8/9. We also present new converse upper bounds on the capacity of this channel under potentially stochastic encoders and decoders. We also study feedback communication over the more widely studied q-ary alphabet channel under additive noise. For the q -ary channel, where q > 2, it is well known that capacity is positive under full feedback if and only if the adversary can corrupt strictly less than half the transmitted symbols. We generalize this result and show that the same threshold holds for positive rate communication when the noiseless feedback may only be partial; our scheme employs a stochastic decoder. We extend this characterization, albeit partially, to fully deterministic schemes under partial noiseless feedback. We also present new converse upper bounds for q-ary channels under full feedback, where the encoder and/or decoder may privately randomize. Our converse results bring to the fore an interesting alternate expression for the well known converse bound for the q—ary channel under full feedback which, when specialized to the binary channel, also equals its known capacity."}],"publisher":"IEEE","type":"conference","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","title":"On the capacity of additive AVCs with feedback","page":"504-509","year":"2022","status":"public","volume":2022,"citation":{"short":"P. Joshi, A. Purkayastha, Y. Zhang, A.J. Budkuley, S. Jaggi, in:, 2022 IEEE International Symposium on Information Theory, IEEE, 2022, pp. 504–509.","ama":"Joshi P, Purkayastha A, Zhang Y, Budkuley AJ, Jaggi S. On the capacity of additive AVCs with feedback. In: <i>2022 IEEE International Symposium on Information Theory</i>. Vol 2022. IEEE; 2022:504-509. doi:<a href=\"https://doi.org/10.1109/ISIT50566.2022.9834850\">10.1109/ISIT50566.2022.9834850</a>","apa":"Joshi, P., Purkayastha, A., Zhang, Y., Budkuley, A. J., &#38; Jaggi, S. (2022). On the capacity of additive AVCs with feedback. In <i>2022 IEEE International Symposium on Information Theory</i> (Vol. 2022, pp. 504–509). Espoo, Finland: IEEE. <a href=\"https://doi.org/10.1109/ISIT50566.2022.9834850\">https://doi.org/10.1109/ISIT50566.2022.9834850</a>","chicago":"Joshi, Pranav, Amritakshya Purkayastha, Yihan Zhang, Amitalok J. Budkuley, and Sidharth Jaggi. “On the Capacity of Additive AVCs with Feedback.” In <i>2022 IEEE International Symposium on Information Theory</i>, 2022:504–9. IEEE, 2022. <a href=\"https://doi.org/10.1109/ISIT50566.2022.9834850\">https://doi.org/10.1109/ISIT50566.2022.9834850</a>.","mla":"Joshi, Pranav, et al. “On the Capacity of Additive AVCs with Feedback.” <i>2022 IEEE International Symposium on Information Theory</i>, vol. 2022, IEEE, 2022, pp. 504–09, doi:<a href=\"https://doi.org/10.1109/ISIT50566.2022.9834850\">10.1109/ISIT50566.2022.9834850</a>.","ista":"Joshi P, Purkayastha A, Zhang Y, Budkuley AJ, Jaggi S. 2022. On the capacity of additive AVCs with feedback. 2022 IEEE International Symposium on Information Theory. ISIT: Internation Symposium on Information Theory vol. 2022, 504–509.","ieee":"P. Joshi, A. Purkayastha, Y. Zhang, A. J. Budkuley, and S. Jaggi, “On the capacity of additive AVCs with feedback,” in <i>2022 IEEE International Symposium on Information Theory</i>, Espoo, Finland, 2022, vol. 2022, pp. 504–509."},"day":"03","intvolume":"      2022","conference":{"end_date":"2022-07-01","name":"ISIT: Internation Symposium on Information Theory","location":"Espoo, Finland","start_date":"2022-06-26"},"date_created":"2022-09-04T22:02:04Z","article_processing_charge":"No","scopus_import":"1","date_updated":"2022-09-05T10:23:35Z","_id":"12013","language":[{"iso":"eng"}],"date_published":"2022-08-03T00:00:00Z","quality_controlled":"1","department":[{"_id":"MaMo"}],"publication_identifier":{"isbn":["9781665421591"],"issn":["2157-8095"]},"doi":"10.1109/ISIT50566.2022.9834850","month":"08","publication_status":"published","publication":"2022 IEEE International Symposium on Information Theory","author":[{"full_name":"Joshi, Pranav","first_name":"Pranav","last_name":"Joshi"},{"first_name":"Amritakshya","last_name":"Purkayastha","full_name":"Purkayastha, Amritakshya"},{"id":"2ce5da42-b2ea-11eb-bba5-9f264e9d002c","full_name":"Zhang, Yihan","last_name":"Zhang","first_name":"Yihan"},{"full_name":"Budkuley, Amitalok J.","last_name":"Budkuley","first_name":"Amitalok J."},{"full_name":"Jaggi, Sidharth","last_name":"Jaggi","first_name":"Sidharth"}]}