Spectral and Power Efficient Modulation Methods in Presence of Nonlinear Distortions

Markku Kiviranta

Spectral and Power Efficient Modulation Methods in Presence of Nonlinear Distortions

Julkaisun otsikon käännös: Spektri- ja energiatehokkaat modulaatiomenetelmät epälineaaristen vääristymien läsnä ollessa

Markku Kiviranta

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Väitöskirja sisältää kirjallisuuskatsauksen ja esittää uusia tuloksia tulevaisuuden 5G-järjestelmien aaltomuodon suunnitteluun analogiaosien aiheuttamien vääristymien läsnäollessa. Tyypillisille epälineaarisuuksille lähettimessä ja vastaanottimessa esitetään järjestelmämalli, joka sisältää myös kanavan. Erityistä huomiota kiinnitetään epälineaariseen tehovahvistimeen, vaihekohinaan ja DC offsetiin. Väitöskirjassa keskitytään 4G-järjestelmissä käytettävän OFDM (orthogonal frequency division multiplexing) monikantoaaltotekniikan jatkokehittämiseen, koska 4G-evoluution oletetaan olevan riittävän kypsä tulevaisuuden 5G-järjestelmien demonstroinneille. Erityistä huomiota kiinnitetään vaihemodulaation avulla saavutettavaan vakioverhokäyräiseen OFDM-modulaatioon. Suorituskykytulokset osoittavat, että vakioverhokäyräisellä OFDM-järjestelmällä on etu vastaavaan OFDM-järjestelmään nähden, kun lähettimen tehovahvistimen hyötysuhde otetaan huomioon simuloinneissa. Vakioverhokäyräinen OFDM sietää myös paremmin vaihekohinaa, koska vaihekohina muuttuu summa termiksi vaiheilmaisen lähdössä. Vakioverhokäyräinen OFDM on mielenkiintoinen vaihtoehto 5G-järjestelmille, kun energiatehokkuus on tärkeämpi kriteeri kuin spektrin tehokkuus. Väitöskirjassa esitetään myös uusia tuloksia vakioverhokäyräiselle TFM-modulaatiolle (tamed frequency modulation), jonka kaistan ulkopuolinen säteily on pieni verrattuna muihin tunnettuihin CPM-modulaatiomenetelmiin (continuous phase modulation). Vaihe- ja taajuusmodulaatiossa kaistanleveyttä ja ilmaisun suorituskykyä säädetään modulaatioindeksin avulla. TFM-modulaation yksinkertaisessa analogiatoteutuksessa modulaatioindeksi poikkeaa kuitenkin asetetusta nimellisarvosta lähetyksen aikana aiheuttaen vaihevärinää. Ilmaisun suorituskyvyn parantamiseksi tässä työssä esitetään uusi modulaatioindeksin estimaattori vastaanottimessa yhdistettynä selviytyjäkohtaista käsittelyä (per-survivor processing, PSP) hyödyntävään kantoaallon vaiheen estimointiin. Väitöskirjassa esitetään myös uusia tuloksia TCM-modulaatiolle (trellis-coded modulation), joka on yhdistetty koodaus- ja modulaatiomenetelmä teho- ja kaistarajoitetuille järjestelmille. Työssä osoitetaan, että hyödyntämällä niin sanottua moni-trelliskoodattua modulaatiota (multiple trellis-coded modulation), PSP-kantoaallon vaihesynkronointia ja Reed–Solomon (RS) koodausta voidaan TCM-modulaatio estää tulemasta katastrofaaliseksi koodiksi vaihekohinan yhteydessä. TCM- ja CPM-menetelmät voivat täydentää tulevaisuuden OFDM pohjaisia 5G-järjestelmiä.

Julkaisun otsikon käännös	Spektri- ja energiatehokkaat modulaatiomenetelmät epälineaaristen vääristymien läsnä ollessa
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Wichman, Risto, Vastuuprofessori Mämmelä, Aarne, Ohjaaja, Ulkoinen henkilö
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-7356-9, 978-951-38-8526-7
Sähköinen ISBN	978-952-60-7355-2, 978-951-38-8525-0
Tila	Julkaistu - 2017
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

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http://urn.fi/URN:ISBN:978-952-60-7355-2Lisenssi: Määrittelemätön

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@phdthesis{776795e8a93647f3b934c778d46bc760,

title = "Spectral and Power Efficient Modulation Methods in Presence of Nonlinear Distortions",

abstract = "This thesis presents a state-of-the-art review and brings new contributions to the waveform design for 5G systems in the presence of analog nonlinearities. A system model for the typical analog impairments at each stage of the transmitter and the receiver with a channel is first presented. The highlighted nonlinearities are power amplifier (PA), phase noise, and DC offset. In this thesis, the further development of the orthogonal frequency division multiplexing (OFDM) is considered since the evolutionary approach from the 4G to the 5G is assumed to be more mature for technology demonstrations. In particular, the constant envelope OFDM (CE-OFDM) where phase modulation creates a constant envelope is studied, and the results indicate that CE-OFDM has an advantage compared to OFDM when the PA efficiency is taken into account in the simulations. Since the phase noise transforms just into an additive noise term after the phase detector, CE-OFDM is very resistant to phase noise unlike OFDM. CE-OFDM can be seen as an interesting candidate for the 5G scenarios when the power efficiency is a more important parameter than the spectral efficiency. This thesis presents also new findings and results for the constant envelope tamed frequency modulation (TFM) and trellis-coded modulation (TCM) that is a traditional combined coding and modulation technique for spectral and power limited systems. In phase or frequency modulation spectral spreading and detection performance are controlled using a modulation index. In a simple analog implementation of TFM, the modulation index deviates during the transmission and generates time varying phase jitter. In this work a modulation index estimator in conjunction with per-survivor processing (PSP) carrier phase estimation is presented for the TFM which has also very small spectral out-of-band radiation compared to other known CPM methods. A novel scheme based on multiple TCM, PSP and Reed–Solomon (RS) coding is proposed and shown to prevent the trellis-code to become a catastrophic code in the presence of phase noise. In general, the TCM and CPM modulations can complement the future adaptive OFDM based 5G systems.",

keywords = "continuous phase modulation (CPM), constant envelope orthogonal frequency division multiplexing (CE-OFDM), nonlinearity, tamed frequency modulation (TFM), trellis-coded modulation (TCM), continuous phase modulation (CPM), constant envelope orthogonal frequency division multiplexing (CE-OFDM), nonlinearity, tamed frequency modulation (TFM), trellis-coded modulation (TCM)",

author = "Markku Kiviranta",

year = "2017",

language = "English",

isbn = "978-952-60-7356-9",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "56",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Spectral and Power Efficient Modulation Methods in Presence of Nonlinear Distortions

AU - Kiviranta, Markku

PY - 2017

Y1 - 2017

N2 - This thesis presents a state-of-the-art review and brings new contributions to the waveform design for 5G systems in the presence of analog nonlinearities. A system model for the typical analog impairments at each stage of the transmitter and the receiver with a channel is first presented. The highlighted nonlinearities are power amplifier (PA), phase noise, and DC offset. In this thesis, the further development of the orthogonal frequency division multiplexing (OFDM) is considered since the evolutionary approach from the 4G to the 5G is assumed to be more mature for technology demonstrations. In particular, the constant envelope OFDM (CE-OFDM) where phase modulation creates a constant envelope is studied, and the results indicate that CE-OFDM has an advantage compared to OFDM when the PA efficiency is taken into account in the simulations. Since the phase noise transforms just into an additive noise term after the phase detector, CE-OFDM is very resistant to phase noise unlike OFDM. CE-OFDM can be seen as an interesting candidate for the 5G scenarios when the power efficiency is a more important parameter than the spectral efficiency. This thesis presents also new findings and results for the constant envelope tamed frequency modulation (TFM) and trellis-coded modulation (TCM) that is a traditional combined coding and modulation technique for spectral and power limited systems. In phase or frequency modulation spectral spreading and detection performance are controlled using a modulation index. In a simple analog implementation of TFM, the modulation index deviates during the transmission and generates time varying phase jitter. In this work a modulation index estimator in conjunction with per-survivor processing (PSP) carrier phase estimation is presented for the TFM which has also very small spectral out-of-band radiation compared to other known CPM methods. A novel scheme based on multiple TCM, PSP and Reed–Solomon (RS) coding is proposed and shown to prevent the trellis-code to become a catastrophic code in the presence of phase noise. In general, the TCM and CPM modulations can complement the future adaptive OFDM based 5G systems.

AB - This thesis presents a state-of-the-art review and brings new contributions to the waveform design for 5G systems in the presence of analog nonlinearities. A system model for the typical analog impairments at each stage of the transmitter and the receiver with a channel is first presented. The highlighted nonlinearities are power amplifier (PA), phase noise, and DC offset. In this thesis, the further development of the orthogonal frequency division multiplexing (OFDM) is considered since the evolutionary approach from the 4G to the 5G is assumed to be more mature for technology demonstrations. In particular, the constant envelope OFDM (CE-OFDM) where phase modulation creates a constant envelope is studied, and the results indicate that CE-OFDM has an advantage compared to OFDM when the PA efficiency is taken into account in the simulations. Since the phase noise transforms just into an additive noise term after the phase detector, CE-OFDM is very resistant to phase noise unlike OFDM. CE-OFDM can be seen as an interesting candidate for the 5G scenarios when the power efficiency is a more important parameter than the spectral efficiency. This thesis presents also new findings and results for the constant envelope tamed frequency modulation (TFM) and trellis-coded modulation (TCM) that is a traditional combined coding and modulation technique for spectral and power limited systems. In phase or frequency modulation spectral spreading and detection performance are controlled using a modulation index. In a simple analog implementation of TFM, the modulation index deviates during the transmission and generates time varying phase jitter. In this work a modulation index estimator in conjunction with per-survivor processing (PSP) carrier phase estimation is presented for the TFM which has also very small spectral out-of-band radiation compared to other known CPM methods. A novel scheme based on multiple TCM, PSP and Reed–Solomon (RS) coding is proposed and shown to prevent the trellis-code to become a catastrophic code in the presence of phase noise. In general, the TCM and CPM modulations can complement the future adaptive OFDM based 5G systems.

KW - continuous phase modulation (CPM)

KW - constant envelope orthogonal frequency division multiplexing (CE-OFDM)

KW - nonlinearity

KW - tamed frequency modulation (TFM)

KW - trellis-coded modulation (TCM)

KW - continuous phase modulation (CPM)

KW - constant envelope orthogonal frequency division multiplexing (CE-OFDM)

KW - nonlinearity

KW - tamed frequency modulation (TFM)

KW - trellis-coded modulation (TCM)

M3 - Doctoral Thesis

SN - 978-952-60-7356-9

SN - 978-951-38-8526-7

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Spectral and Power Efficient Modulation Methods in Presence of Nonlinear Distortions

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