{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/81326"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/81326","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"A Framework for Spectrally Efficient Noncoherent Communication","abstract":"\"This thesis considers noncoherent communication over a frequency-nonselective channel in which the time-varying channel gain is unknown a priori , but is approximately constant over a coherence interval . Unless the coherence interval is large, coherent communication, which requires explicit channel estimation and tracking prior to detection, incurs training overhead which may be excessive, especially for multiple antenna communication. In contrast, noncoherent detection, which may be viewed as a generalized likelihood ratio test (GLRT) for joint channel and data estimation, does not require separate training. The goal of this thesis is to provide a framework for designing spectrally efficient noncoherent communication systems, analogous to the wealth of signal and code design techniques available for coherent communication. The main results are as follows: (1) A \"\"signal space\"\" criterion is developed for signal and code design for noncoherent communication, in terms of the distances of signal points from the decision boundaries. (2) The noncoherent metric thus obtained is used to guide the design of signals for noncoherent communication that are based on amplitude/phase constellations. These are significantly more efficient than conventional differential phase shift keying (PSK), especially at high signal-to-noise ratio (SNR). Also, known results on the high SNR performance of multiple symbol demodulation of differential PSK are easily inferred from the noncoherent metric. (3) The GLRT interpretation is used to obtain a linear complexity (in the block length) implementation of multiple symbol demodulation of differential PSK. The degradation of this scheme from the exact, exponential complexity, implementation can be made as small as desired. (4) A block transformation is demonstrated to produce noncoherent space-time codes with full diversity, starting from an appropriately chosen single antenna noncoherent code. This provides a constructive approach for obtaining high rate noncoherent space-time codes for large coherence intervals. Previous optimization approaches to finding noncoherent space-time codes would be difficult to implement in such a setting, since they involve a search over a space whose dimensions grow exponentially with the block length and the code rate.\"","abstract_html":""This thesis considers noncoherent communication over a frequency-nonselective channel in which the time-varying channel gain is unknown a priori , but is approximately constant over a coherence interval . Unless the coherence interval is large, coherent communication, which requires explicit channel estimation and tracking prior to detection, incurs training overhead which may be excessive, especially for multiple antenna communication. In contrast, noncoherent detection, which may be viewed as a generalized likelihood ratio test (GLRT) for joint channel and data estimation, does not require separate training. The goal of this thesis is to provide a framework for designing spectrally efficient noncoherent communication systems, analogous to the wealth of signal and code design techniques available for coherent communication. The main results are as follows: (1) A ""signal space"" criterion is developed for signal and code design for noncoherent communication, in terms of the distances of signal points from the decision boundaries. (2) The noncoherent metric thus obtained is used to guide the design of signals for noncoherent communication that are based on amplitude/phase constellations. These are significantly more efficient than conventional differential phase shift keying (PSK), especially at high signal-to-noise ratio (SNR). Also, known results on the high SNR performance of multiple symbol demodulation of differential PSK are easily inferred from the noncoherent metric. (3) The GLRT interpretation is used to obtain a linear complexity (in the block length) implementation of multiple symbol demodulation of differential PSK. The degradation of this scheme from the exact, exponential complexity, implementation can be made as small as desired. (4) A block transformation is demonstrated to produce noncoherent space-time codes with full diversity, starting from an appropriately chosen single antenna noncoherent code. This provides a constructive approach for obtaining high rate noncoherent space-time codes for large coherence intervals. Previous optimization approaches to finding noncoherent space-time codes would be difficult to implement in such a setting, since they involve a search over a space whose dimensions grow exponentially with the block length and the code rate."","abstract_has_math":false,"creators":["Warrier, Dilip Gopinath"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical Engineering","degree_department":null,"school":null,"contributors":["Upamanyu Madhow"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T20:10:35Z","date_published":"2015-09-25T20:10:35Z","updated_at":"2026-07-22T22:26:16Z","subjects":["Engineering, Electronics and Electrical"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI9955679"],"render_values":[{"text":"(MiAaPQ)AAI9955679","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/81326","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Upamanyu Madhow"]},{"key":"dc:creator","label":"Author","values":["Warrier, Dilip Gopinath"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T20:10:35Z","10000-01-01","2000"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Electronics and Electrical"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/81326","(MiAaPQ)AAI9955679"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"This thesis considers noncoherent communication over a frequency-nonselective channel in which the time-varying channel gain is unknown a priori , but is approximately constant over a coherence interval . Unless the coherence interval is large, coherent communication, which requires explicit channel estimation and tracking prior to detection, incurs training overhead which may be excessive, especially for multiple antenna communication. In contrast, noncoherent detection, which may be viewed as a generalized likelihood ratio test (GLRT) for joint channel and data estimation, does not require separate training. The goal of this thesis is to provide a framework for designing spectrally efficient noncoherent communication systems, analogous to the wealth of signal and code design techniques available for coherent communication. The main results are as follows: (1) A \"\"signal space\"\" criterion is developed for signal and code design for noncoherent communication, in terms of the distances of signal points from the decision boundaries. (2) The noncoherent metric thus obtained is used to guide the design of signals for noncoherent communication that are based on amplitude/phase constellations. These are significantly more efficient than conventional differential phase shift keying (PSK), especially at high signal-to-noise ratio (SNR). Also, known results on the high SNR performance of multiple symbol demodulation of differential PSK are easily inferred from the noncoherent metric. (3) The GLRT interpretation is used to obtain a linear complexity (in the block length) implementation of multiple symbol demodulation of differential PSK. The degradation of this scheme from the exact, exponential complexity, implementation can be made as small as desired. (4) A block transformation is demonstrated to produce noncoherent space-time codes with full diversity, starting from an appropriately chosen single antenna noncoherent code. This provides a constructive approach for obtaining high rate noncoherent space-time codes for large coherence intervals. Previous optimization approaches to finding noncoherent space-time codes would be difficult to implement in such a setting, since they involve a search over a space whose dimensions grow exponentially with the block length and the code rate.\"","Made available in DSpace on 2015-09-25T20:10:35Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9955679.pdf: 3178513 bytes, checksum: 36e1e52873ab9bb7486aab7181874266 (MD5) Previous issue date: 2000","Embargo set by: Seth Robbins for item 82607 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","76 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000."]},{"key":"dc:title","label":"Title","values":["A Framework for Spectrally Efficient Noncoherent Communication"]}]}],"canonical_facts":{"dc:contributor":["Upamanyu Madhow"],"dc:creator":["Warrier, Dilip Gopinath"],"dc:date":["2015-09-25T20:10:35Z","10000-01-01","2000"],"dc:description":["\"This thesis considers noncoherent communication over a frequency-nonselective channel in which the time-varying channel gain is unknown a priori , but is approximately constant over a coherence interval . Unless the coherence interval is large, coherent communication, which requires explicit channel estimation and tracking prior to detection, incurs training overhead which may be excessive, especially for multiple antenna communication. In contrast, noncoherent detection, which may be viewed as a generalized likelihood ratio test (GLRT) for joint channel and data estimation, does not require separate training. The goal of this thesis is to provide a framework for designing spectrally efficient noncoherent communication systems, analogous to the wealth of signal and code design techniques available for coherent communication. The main results are as follows: (1) A \"\"signal space\"\" criterion is developed for signal and code design for noncoherent communication, in terms of the distances of signal points from the decision boundaries. (2) The noncoherent metric thus obtained is used to guide the design of signals for noncoherent communication that are based on amplitude/phase constellations. These are significantly more efficient than conventional differential phase shift keying (PSK), especially at high signal-to-noise ratio (SNR). Also, known results on the high SNR performance of multiple symbol demodulation of differential PSK are easily inferred from the noncoherent metric. (3) The GLRT interpretation is used to obtain a linear complexity (in the block length) implementation of multiple symbol demodulation of differential PSK. The degradation of this scheme from the exact, exponential complexity, implementation can be made as small as desired. (4) A block transformation is demonstrated to produce noncoherent space-time codes with full diversity, starting from an appropriately chosen single antenna noncoherent code. This provides a constructive approach for obtaining high rate noncoherent space-time codes for large coherence intervals. Previous optimization approaches to finding noncoherent space-time codes would be difficult to implement in such a setting, since they involve a search over a space whose dimensions grow exponentially with the block length and the code rate.\"","Made available in DSpace on 2015-09-25T20:10:35Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9955679.pdf: 3178513 bytes, checksum: 36e1e52873ab9bb7486aab7181874266 (MD5) Previous issue date: 2000","Embargo set by: Seth Robbins for item 82607 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","76 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000."],"dc:identifier":["http://hdl.handle.net/2142/81326","(MiAaPQ)AAI9955679"],"dc:language":["eng"],"dc:subject":["Engineering, Electronics and Electrical"],"dc:title":["A Framework for Spectrally Efficient Noncoherent Communication"],"dc:type":["text"],"thesis:degree_discipline":["Electrical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:16Z"}