DM-OFDM Sistemlerinin Donanım Kusurları ve Çeşitli Kanal Koşulları Altında Performans Analizi

Öz

Bu çalışma, donanım kusurları ve değişken kanal koşulları altında Çift modlu indis modülasyonu destekli ortogonal frekans bölmeli çoğullama (DM-OFDM) sistemlerinin performansını incelemektedir. Çift modluluğun sağladığı spektral verimlilik, klasik indis modülasyonlu OFDM (OFDM-IM) ile karşılaştırmalı olarak Rayleigh ve Rician sönümlü kanallarında analiz edilmiştir. Faz gürültüsü ve IQ dengesizliği gibi pratik donanım kusurları modele dahil edilerek etkileri değerlendirilmiştir. Farklı alt taşıyıcı sayıları (N=64/128/256) ve aktif alt taşıyıcı konfigürasyonları (K=1/2/3) için yapılan simülasyonlar, DM-OFDM’in her iki kanal koşulunda da klasik OFDM-IM’den üstün bit hata oranı (BER) performansı sağladığını göstermektedir. Yüksek sinyal gürültü oranı (SNR) bölgelerinde donanım bozulmalarına bağlı hata tabanı oluştuğu gözlemlenmiş ve bu etkinin sistem tasarımında dikkate alınması gerektiği vurgulanmıştır. Alt taşıyıcı sayısının artırılması ve aktif taşıyıcı seçiminin optimize edilmesi performansı iyileştirirken, Rician kanalındaki görüş hattı bileşeni performansı daha da artırmaktadır.

Anahtar Kelimeler

• OFDM
• İndis Modülasyonu
• Donanım Kusurları
• Bit Hata Oranı

Performance Analysis of DM-OFDM Systems Under Hardware Impairments and Various Channel Conditions

Öz

This study investigates the performance of Dual-mode index modulation aided orthogonal frequency division multiplexing (DM-OFDM) systems under hardware impairments and varying channel conditions. The spectral efficiency provided by dual-mode operation is analyzed in comparison to conventional index modulation OFDM (OFDM-IM) over Rayleigh and Rician fading channels. Practical hardware impairments, such as phase noise and IQ imbalance, are incorporated into the model to evaluate their effects. Simulations conducted for different subcarrier numbers (N=64/128/256) and active subcarrier configurations (K=1/2/3) demonstrate that DM-OFDM outperforms conventional OFDM-IM in terms of bit error rate (BER) performance under both channel conditions. In high signal to noise ratio (SNR) regions, an error floor caused by hardware distortions is observed, emphasizing the need to consider this effect in system design. While increasing the number of subcarriers and optimizing active subcarrier selection enhances performance, the line-of-sight component in the Rician channel further improves the system's performance.

Anahtar Kelimeler

• OFDM
• Index Modulation
• Hardware Impairments
• Bit Error Rated

Kaynakça

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