Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems
<p><span style="font-size: 11pt; line-height: 125%; font-family: Calibri, sans-serif;">Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) is a system that exhibits superior power efficiency and bandwidth compared to the conventional OFDM system. In the O...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | fas |
| Published: |
Islamic Azad University Bushehr Branch
2025-04-01
|
| Series: | مهندسی مخابرات جنوب |
| Subjects: | |
| Online Access: | https://sanad.iau.ir/journal/jce/Article/870011 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850269490296651776 |
|---|---|
| author | Farshad Jalili kharajoo SeyyedHadi SeyyedMasoumian Charandabi |
| author_facet | Farshad Jalili kharajoo SeyyedHadi SeyyedMasoumian Charandabi |
| author_sort | Farshad Jalili kharajoo |
| collection | DOAJ |
| description | <p><span style="font-size: 11pt; line-height: 125%; font-family: Calibri, sans-serif;">Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) is a system that exhibits superior power efficiency and bandwidth compared to the conventional OFDM system. In the OFDM-IM system, some subcarriers are inactive, and instead of transmitting modulation symbols, zero values are sent on these subcarriers. Additionally, in the OFDM-IM system, data is transmitted through the inactive subcarriers based on their specific locations. This paper aims to determine the optimal number of active subcarriers to maximize the transmitted data rate and spectral efficiency of the OFDM-IM system. Through mathematical relationships and simulation results, it is demonstrated that the identified value of active subcarriers is indeed optimal, leading to the maximization of the data rate of the system and spectral efficiency. The proposed optimal method, particularly designed for 4-symbol Pulse Amplitude Modulation and 8-group OFDM-IM, has resulted in a 6.25% increase in the number of transmitted bits compared to previous methods. As a secondary objective, a modified constellation with equal intervals is introduced for M-PAM modulation, aiming to reduce the bit error rate of the OFDM-IM system and enhance overall system performance. Simulation results and bit error rate curves illustrate the effectiveness of the proposed constellation. For 4-symbol Pulse Amplitude Modulation and 16-group OFDM-IM, utilizing 9 active subcarriers and a signal-to-noise ratio of 12 dB, the proposed constellation has demonstrated a tenfold improvement in the bit error rate of the system.</span></p> |
| format | Article |
| id | doaj-art-45fb10fa57304fc4b58bf49fa2e83f7d |
| institution | OA Journals |
| issn | 2980-9231 |
| language | fas |
| publishDate | 2025-04-01 |
| publisher | Islamic Azad University Bushehr Branch |
| record_format | Article |
| series | مهندسی مخابرات جنوب |
| spelling | doaj-art-45fb10fa57304fc4b58bf49fa2e83f7d2025-08-20T01:53:07ZfasIslamic Azad University Bushehr Branchمهندسی مخابرات جنوب2980-92312025-04-0114555269Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM SystemsFarshad Jalili kharajoo0SeyyedHadi SeyyedMasoumian Charandabi1Department of Electrical Engineering, Tabriz Branch, Islamic Azad University, Tabriz, IranDepartment of Electrical Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran<p><span style="font-size: 11pt; line-height: 125%; font-family: Calibri, sans-serif;">Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) is a system that exhibits superior power efficiency and bandwidth compared to the conventional OFDM system. In the OFDM-IM system, some subcarriers are inactive, and instead of transmitting modulation symbols, zero values are sent on these subcarriers. Additionally, in the OFDM-IM system, data is transmitted through the inactive subcarriers based on their specific locations. This paper aims to determine the optimal number of active subcarriers to maximize the transmitted data rate and spectral efficiency of the OFDM-IM system. Through mathematical relationships and simulation results, it is demonstrated that the identified value of active subcarriers is indeed optimal, leading to the maximization of the data rate of the system and spectral efficiency. The proposed optimal method, particularly designed for 4-symbol Pulse Amplitude Modulation and 8-group OFDM-IM, has resulted in a 6.25% increase in the number of transmitted bits compared to previous methods. As a secondary objective, a modified constellation with equal intervals is introduced for M-PAM modulation, aiming to reduce the bit error rate of the OFDM-IM system and enhance overall system performance. Simulation results and bit error rate curves illustrate the effectiveness of the proposed constellation. For 4-symbol Pulse Amplitude Modulation and 16-group OFDM-IM, utilizing 9 active subcarriers and a signal-to-noise ratio of 12 dB, the proposed constellation has demonstrated a tenfold improvement in the bit error rate of the system.</span></p>https://sanad.iau.ir/journal/jce/Article/870011spectral efficiency optimal active subcarrier constellation pattern data rate ofdm-im |
| spellingShingle | Farshad Jalili kharajoo SeyyedHadi SeyyedMasoumian Charandabi Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems مهندسی مخابرات جنوب spectral efficiency optimal active subcarrier constellation pattern data rate ofdm-im |
| title | Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems |
| title_full | Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems |
| title_fullStr | Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems |
| title_full_unstemmed | Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems |
| title_short | Optimization of the Number of Active Subcarriers and M-PAM Modulation Constellation Pattern for OFDM-IM Systems |
| title_sort | optimization of the number of active subcarriers and m pam modulation constellation pattern for ofdm im systems |
| topic | spectral efficiency optimal active subcarrier constellation pattern data rate ofdm-im |
| url | https://sanad.iau.ir/journal/jce/Article/870011 |
| work_keys_str_mv | AT farshadjalilikharajoo optimizationofthenumberofactivesubcarriersandmpammodulationconstellationpatternforofdmimsystems AT seyyedhadiseyyedmasoumiancharandabi optimizationofthenumberofactivesubcarriersandmpammodulationconstellationpatternforofdmimsystems |