Impact of I/Q Imbalance Due to Gain and Phase Mismatches on IRR, Image Leakage, Constellation Distortion, SNR and BER in OFDM Systems

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Year : 2026 | Volume : 12 | 02 | Page :
By

Yashvi Mojidra,

Vidhi Sheth,

Rizwan Alad,

Nirav Desai,

Ashish Pandya,

Purvang Dalal,

  1. Student, Department of Electronics & Communication Engineering, Dharmsinh Desai University, Nadiad, Gujarat, India
  2. Student, Department of Electronics & Communication Engineering, Dharmsinh Desai University, Nadiad, Gujarat, India
  3. Associate Professor, Department of Electronics & Communication Engineering, Dharmsinh Desai University, Nadiad, Gujarat, India
  4. Assistant Professor, Department of Electronics and Communication Engineering, Dharmsinh Desai University, Nadiad, Gujarat, India
  5. Assistant Professor, Department of Electronics and Communication Engineering, Dharmsinh Desai University, Nadiad, Gujarat, India
  6. Professor and Head, Department of Electronics and Communication Engineering, Dharmsinh Desai University, Nadiad, Gujarat, India

Abstract

Due to its great spectral efficiency and resilience to multipath fading, orthogonal frequency division multiplexing, or OFDM, has become a popular modulation technique in contemporary wireless communication systems. Reliable OFDM reception depends on accurate channel estimate, and methods like Least Squares (LS) and Minimum Mean Square Error (MMSE) estimation are frequently used to make up for channel impairments. However, despite effective channel estimation, practical receiver performance can still be degraded by radio- frequency front-end imperfections, particularly I/Q imbalance caused by gain and phase mismatches between the in-phase and quadrature branches. This work investigates the impact of I/Q imbalance on OFDM receiver performance. A mathematical model incorporating gain and phase mismatches is developed, and the resulting Image Rejection Ratio (IRR) is analyzed as a key indicator of receiver impairment. The relationship between IRR and image leakage is examined to demonstrate how increased image signal power reduces the receiver’s image suppression capability. Furthermore, the effect of image leakage on 64-QAM constellation distortion is analyzed under gain mismatch, phase mismatch, and combined imbalance conditions. The resulting constellation distortion is shown to degrade the effective Signal-to-Noise Ratio (SNR), which subsequently increases the Bit Error Rate (BER). Numerical results including IRR, image leakage, constellation diagrams, SNR performance, and BER characteristics are presented to evaluate the overall impact of I/Q imbalance on OFDM communication systems. The study provides a comprehensive understanding of the degradation mechanisms introduced by receiver-side RF impairments and their influence on communication reliability.

Keywords: I/Q Imbalance; OFDM Systems; Image Rejection Ratio (IRR); 64-QAM; Bit Error Rate (BER).

How to cite this article: Yashvi Mojidra, Vidhi Sheth, Rizwan Alad, Nirav Desai, Ashish Pandya, Purvang Dalal. Impact of I/Q Imbalance Due to Gain and Phase Mismatches on IRR, Image Leakage, Constellation Distortion, SNR and BER in OFDM Systems. International Journal of Microwave Engineering and Technology. 2026; 12(02):-.
How to cite this URL: Yashvi Mojidra, Vidhi Sheth, Rizwan Alad, Nirav Desai, Ashish Pandya, Purvang Dalal. Impact of I/Q Imbalance Due to Gain and Phase Mismatches on IRR, Image Leakage, Constellation Distortion, SNR and BER in OFDM Systems. International Journal of Microwave Engineering and Technology. 2026; 12(02):-. Available from: https://journals.stmjournals.com/ijmet/article=2026/view=255231

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Ahead of Print Subscription Review Article
Volume 12
02
Received 03/09/2026
Accepted 07/09/2026
Published 10/09/2026
Publication Time 7 Days

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