{"id":151,"date":"2022-02-28T18:41:15","date_gmt":"2022-02-28T17:41:15","guid":{"rendered":"https:\/\/project.inria.fr\/wassap\/?page_id=151"},"modified":"2022-02-28T19:09:10","modified_gmt":"2022-02-28T18:09:10","slug":"wp3","status":"publish","type":"page","link":"https:\/\/project.inria.fr\/wassap\/wp3\/","title":{"rendered":"Signal processing, modulation and waveforms."},"content":{"rendered":"<p>The signal processing part (WP3) of WASSAP consists in:<\/p>\n<ul>\n<li>Selecting a well-suited waveform for sub-THz communications, based on its robustness to sub-THz impairments (phase noise, non-linearities, I\/Q mismatch),<\/li>\n<li>Studying the synchronization at the receiver (frequency, timing and phase),<\/li>\n<li>Forward Error Coding (FEC).<\/li>\n<\/ul>\n<p>As of now, FEC has not been studied. It will be investigated once the other parameters (waveform, carrier frequency, bandwidth) have been chosen.<\/p>\n<p>Multiple waveforms have been studied, from linear Phase-and-Amplitude Modulations (PAM) to non-linear Continuous Phase Modulations (CPM). These waveforms have been compated with each other, bearing in mind the phase noise as a main impairment. This study lead to 2 publications [1-2]. The main results of this study are shown in the figure below:<\/p>\n<p><a href=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01a.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-163\" src=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01a-279x300.jpg\" alt=\"\" width=\"279\" height=\"300\" srcset=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01a-279x300.jpg 279w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01a-139x150.jpg 139w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01a.jpg 411w\" sizes=\"auto, (max-width: 279px) 100vw, 279px\" \/><\/a> <a href=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01b.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-164\" src=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01b-281x300.jpg\" alt=\"\" width=\"281\" height=\"300\" srcset=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01b-281x300.jpg 281w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01b-140x150.jpg 140w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01b.jpg 418w\" sizes=\"auto, (max-width: 281px) 100vw, 281px\" \/><\/a> <a href=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01c.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-165\" src=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01c-279x300.jpg\" alt=\"\" width=\"279\" height=\"300\" srcset=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01c-279x300.jpg 279w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01c-139x150.jpg 139w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_01c.jpg 529w\" sizes=\"auto, (max-width: 279px) 100vw, 279px\" \/><\/a><\/p>\n<p>Fig. 1 Left: Comparison without phase noise. Center: Comparison with medium phase noise. Right: Comparison with strong phase noise.<\/p>\n<p>Three &#8220;good candidates&#8221; have been studied with the help of Institut Foton:<\/p>\n<ol>\n<li><strong>GMSK<\/strong> (Gaussian Minimum Shift Keying), which will be cast out later in favor of the Raised Cosine (RC) CPM,<\/li>\n<li><strong>FSIM<\/strong> (Filter Shapes Index Modulation): a PAM modulation with the addition of virtual bits, see Saad\u2019s work [3] for further details.<\/li>\n<li><span style=\"font-family: 'Source Sans Pro';\">The <strong>spiral modulation<\/strong> [4], still at the simulation level. It is a PAM modulation that has the shape of a spiral, with one or more branches, depending on a parameter to optimize. This waveform is theoretically robust to phase noise. Once this waveform has been completely understood, experiments will be done to compare it to the other candidates.<\/span><\/li>\n<\/ol>\n<p>Some experiments have been also conducted during the last six months, with the team from Institut Foton at ENSSAT (Lannion). An experimental campaign of three days was carried out at their lab in June 2021. Up to now, only three different systems have been used to test the waveforms in a wired, controlled lab scenario:<\/p>\n<p style=\"text-align: center;\">Electrical transmission (coaxial cable), with intermediate frequency at 10 GHz,<\/p>\n<p><a href=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02a.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-156 aligncenter\" src=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02a-300x58.jpg\" alt=\"\" width=\"331\" height=\"64\" srcset=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02a-300x58.jpg 300w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02a-768x149.jpg 768w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02a-150x29.jpg 150w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02a.jpg 875w\" sizes=\"auto, (max-width: 331px) 100vw, 331px\" \/><\/a><\/p>\n<p style=\"text-align: center;\">Optical transmission, intermediate frequency at 10 GHz and optical up-conversion at the laser frequency (192.601 THz),<\/p>\n<p><a href=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02b.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-157 aligncenter\" src=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02b-300x156.jpg\" alt=\"\" width=\"335\" height=\"174\" srcset=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02b-300x156.jpg 300w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02b-150x78.jpg 150w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02b.jpg 558w\" sizes=\"auto, (max-width: 335px) 100vw, 335px\" \/><\/a><\/p>\n<p style=\"text-align: center;\">Bi-laser optical transmission, with intermediate frequency at 10 GHz and optical up-conversion at 40 GHz.<\/p>\n<p><a href=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02c.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-158 aligncenter\" src=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02c-300x181.jpg\" alt=\"\" width=\"340\" height=\"205\" srcset=\"https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02c-300x181.jpg 300w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02c-150x90.jpg 150w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02c-250x150.jpg 250w, https:\/\/project.inria.fr\/wassap\/files\/2022\/02\/WP3_02c.jpg 613w\" sizes=\"auto, (max-width: 340px) 100vw, 340px\" \/><\/a><\/p>\n<p>The first two systems (electrical and optical) have one purpose: training. The last system is the one usually used in the sub-THz context, and its purpose is to train at relatively low frequency (40 GHz) before going up in frequencies. The last experiments were done on 19\/11\/2021. New experiments are on the way, with expected results in April\/May.<\/p>\n<ol>\n<li>P. Desombre, H. Far\u00e8s and Y. Lou\u00ebt, \u201cPerformance Comparison of Digital Modulations in the Presence of Gaussian Phase Noise in the Sub-THz Context,\u201d 4th Int. Workshop Mobile THz Systems (IWMTS), Essen, Germany, Aug. 2021, pp. 1-5, doi: https:\/\/doi.org\/10.1109\/IWMTS51331.2021.9486786 .<\/li>\n<li>P. Desombre, H. Far\u00e8s, and Y. Lou\u00ebt \u201cWaveform comparison in the presence of Gaussian Phase Noise in the sub-THz context,\u201d URSI-GASS, Aug 2021, Roma, Italy.<\/li>\n<li>M. Saad, J. Palicot, F. Bader, A. Chamas Al Ghouwayel, and H. Hijazi, \u201cA novel index modulation dimension based on filter domain: Filter shapes index modulation,\u201d IEEE Trans. Commun., pp 1\u20131, 2020.<\/li>\n<li>A. Ugolini, A. Piemontese, and T. Eriksson, \u201cSpiral Constellations for Phase Noise Channels,\u201d IEEE Trans. Commun., vol. 67, no. (11), pp. 7799\u20137810, Nov. 2019.<\/li>\n<\/ol>\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>The signal processing part (WP3) of WASSAP consists in: Selecting a well-suited waveform for sub-THz communications, based on its robustness to sub-THz impairments (phase noise,\u2026<\/p>\n<p> <a class=\"continue-reading-link\" href=\"https:\/\/project.inria.fr\/wassap\/wp3\/\"><span>Continue reading<\/span><i class=\"crycon-right-dir\"><\/i><\/a> <\/p>\n","protected":false},"author":1881,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-151","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/pages\/151","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/users\/1881"}],"replies":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/comments?post=151"}],"version-history":[{"count":10,"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/pages\/151\/revisions"}],"predecessor-version":[{"id":172,"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/pages\/151\/revisions\/172"}],"wp:attachment":[{"href":"https:\/\/project.inria.fr\/wassap\/wp-json\/wp\/v2\/media?parent=151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}