OFDM sistemlerinde farklı modülasyon uygulamalarının kullanımı ve performans karşılaştırması

Year 2024, Volume: 16 Issue: 2, 33 - 43, 30.12.2024

Özkan Sezer , Nihat Daldal , İbrahim Yücedağ

https://doi.org/10.55974/utbd.1539349

Abstract

Öz: OFDM (ortogonal frekans bölmeli çoğullama) sistemleri günümüz radyo frekans spektrumunun en verimli kullanımıdır. Sistem, bir sinyalin eş zamanlı olarak küçük sinyallere bölünerek alıcıya gönderilmesidir. Özellikle yüksek kapasiteli veri iletimi ve çok kullanıcılı sistemlerde ihtiyaç duyulmaktadır. OFDM yöntemi, kullanım amacına bağlı olarak, uygun ve yüksek performanslı bir modülasyon tipi kullanıldığı takdirde en yüksek hızda maksimum doğrulukla veri iletimi sağlamaktadır. Bu çalışmada, öncelikle tek bir hat üzerinden çoklu veri iletimi için bir FDM haberleşme simülasyonu gerçekleştirilmiştir. FDM'de kullanılan taşıyıcı frekansları seçildikten sonra, haberleşmenin yüksek kalitesi de göz önüne alındığında OFDM haberleşme yönteminin gerekliliği kanıtlanmıştır. Bir sonraki aşamada, OFDM yönteminde kullanılan modülasyonların farklı SNR (sinyal gürültü oranı) ve çok yollu sönümlenme değerlerinde BER (Bit hata oranı) değeri hesaplanarak performans karşılaştırmaları yapılmıştır. Bu çalışmada, en yüksek doğrulukta veri iletimini sağlayan modülasyon tipinin belirli değişken değerleri belirlenmiştir. Karşılaştırma sonucunda 8 yollu haberleşme ve 0 SNR'da en iyi BER değeri 0,28 olarak BPSK modülasyon tipinde bulunmuştur. 8 yollu iletim ve 30 SNR ölçümünde ise en düşük BER değeri 0,016 olmuştur. Kullanılan modülasyon tipleri 'BPSK, QPSK, 8PSK, 16QAM, 32QAM, 64QAM' arasında yapılan tüm karşılaştırmalarda en düşük BER değerleri BPSK modülasyon tipinde belirlenmiştir.

Keywords

OFDM, Sayısal Modülasyon, BER

Ethical Statement

Makalemiz başka bir dergiye yüklenmemiştir.

Usage of different modulation applications in OFDM systems and performance comparison

Abstract

OFDM (orthogonal frequency division multiplexing) systems are the most efficient use of today's radio frequency spectrum. The system is the simultaneous splitting of a signal into small signals and sending them to the receiver. It is mainly a need in high-capacity data transfer and multi-user systems. Depending on the usage purpose, the OFDM method provides a data transmission with maximum accuracy at the highest speed as long as an appropriate and high-performance modulation type is used. This study performed an FDM communication simulation primarily for multiple data transmissions over a single line. After selecting the carrier frequencies used in FDM, the necessity of the OFDM communication method is proved when considering the high quality of the communication. In the next phase, performance comparisons were made by calculating the BER (Bit error rate) value at different SNR (signal to noise ratio) and multipath fading values of the modulations used in the OFDM method. Specific variable values that the modulation type providing the highest accuracy data transmission has been determined in this study. As a result of the comparison, the best BER value at 8-way communication and 0 SNR was found at 0.28 in the BPSK modulation type. In 8-way transmission and 30 SNR measurements, the lowest BER value was 0.016. In all comparisons made among the used modulation types 'BPSK, QPSK, 8PSK, 16QAM, 32QAM, 64QAM', the lowest BER values were determined in the BPSK modulation type.

Keywords

OFDM, Digital Communication, BER

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