{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,2,21]],"date-time":"2025-02-21T10:42:29Z","timestamp":1740134549350,"version":"3.37.3"},"reference-count":10,"publisher":"Wiley","license":[{"start":{"date-parts":[[2014,1,1]],"date-time":"2014-01-01T00:00:00Z","timestamp":1388534400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61372098","YB2012B004"],"award-info":[{"award-number":["61372098","YB2012B004"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Scientific Research Project of Hunan Education Department","award":["61372098","YB2012B004"],"award-info":[{"award-number":["61372098","YB2012B004"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Applied Mathematics"],"published-print":{"date-parts":[[2014]]},"abstract":"<jats:p>In wireless communications, knowledge of channel coefficients is required for coherent demodulation. Lloyd-Max iteration is an innovative blind channel estimation method for narrowband fading channels. In this paper, it is proved that blind channel estimation based on single-level Lloyd-Max (SL-LM) iteration is not reliable for nonconstant modulus constellations (NMC). Then, we introduce multilevel Lloyd-Max (ML-LM) iteration to solve this problem. Firstly, by dividing NMC into subsets, Lloyd-Max iteration is used in multilevel. Then, the estimation information is transmitted from one level to another. By doing this, accurate blind channel estimation for NMC is achieved. Moreover, when the number of received symbols is small, we propose the lacking constellations equalization algorithm to reduce the influence of lacking constellations. Finally, phase ambiguity of ML-LM iteration is also investigated in the paper. ML-LM iteration can be more robust to the phase of fading coefficient by dividing NMC into subsets properly. As the signal-to-noise ratio (SNR) increases, numerical results show that the proposed method\u2019s mean-square error curve converges remarkably to the least squares (LS) bound with a small number of iterations.<\/jats:p>","DOI":"10.1155\/2014\/146207","type":"journal-article","created":{"date-parts":[[2014,7,20]],"date-time":"2014-07-20T17:01:59Z","timestamp":1405875719000},"page":"1-7","source":"Crossref","is-referenced-by-count":0,"title":["Blind Channel Estimation Based on Multilevel Lloyd-Max Iteration for Nonconstant Modulus Constellations"],"prefix":"10.1155","volume":"2014","author":[{"given":"Xiaotian","family":"Li","sequence":"first","affiliation":[{"name":"The 54th Research Institute of CETC, Shijiazhuang 050081, China"},{"name":"School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Lei","sequence":"additional","affiliation":[{"name":"School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erbao","family":"Li","sequence":"additional","affiliation":[{"name":"School of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanbin","family":"Li","sequence":"additional","affiliation":[{"name":"The 54th Research Institute of CETC, Shijiazhuang 050081, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","reference":[{"key":"1","doi-asserted-by":"publisher","DOI":"10.1109\/18.312157"},{"key":"2","doi-asserted-by":"publisher","DOI":"10.1109\/78.348133"},{"key":"3","doi-asserted-by":"publisher","DOI":"10.1109\/TSP.2004.842207"},{"key":"4","doi-asserted-by":"publisher","DOI":"10.1109\/TCOMM.2010.01.070549"},{"key":"5","doi-asserted-by":"publisher","DOI":"10.1016\/j.sigpro.2013.08.006"},{"key":"6","doi-asserted-by":"publisher","DOI":"10.1049\/ip-f-2.1991.0048"},{"key":"7","doi-asserted-by":"publisher","DOI":"10.1109\/26.939873"},{"year":"1993","key":"8"},{"key":"9","doi-asserted-by":"publisher","DOI":"10.1109\/TCOMM.2012.051712.110523"},{"year":"2005","key":"11"}],"container-title":["Journal of Applied Mathematics"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/downloads.hindawi.com\/journals\/jam\/2014\/146207.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/jam\/2014\/146207.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/downloads.hindawi.com\/journals\/jam\/2014\/146207.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2016,7,28]],"date-time":"2016-07-28T08:26:21Z","timestamp":1469694381000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.hindawi.com\/journals\/jam\/2014\/146207\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014]]},"references-count":10,"alternative-id":["146207","146207"],"URL":"https:\/\/doi.org\/10.1155\/2014\/146207","relation":{},"ISSN":["1110-757X","1687-0042"],"issn-type":[{"type":"print","value":"1110-757X"},{"type":"electronic","value":"1687-0042"}],"subject":[],"published":{"date-parts":[[2014]]}}}