آشکارسازی همزمان زیرکانالهای همبسته OFDM برای سنجش پهن باند طیف در شبکههای رادیوشناختگر
محورهای موضوعی : مهندسی برق و کامپیوتر
1 - دانشگاه تهران
2 - دانشگاه تهران
کلید واژه: آشکارساز انرژی رادیو شناختگر سنجش پهن باند طیف نشت توان,
چکیده مقاله :
در این مقاله مسأله سنجش پهن باند طیف را در حالتی که کاربران اولیه از مدولاسیون OFDM استفاده میکنند، بررسی میکنیم. در این راستا شکل پالس هر زیرکانال غیر ایده آل فرض شده و در نتیجه بخشی از توان آن به زیرکانالهای مجاور نشت میکند. این پدیده باعث میشود که انرژی اندازهگیری شده از هر زیرکانال (آمارگان تصمیمگیری در آشکارساز انرژی) با اندازهگیری زیرکانالهای دیگر همبستگی پیدا کند. از این رو برای آشکارسازی همزمان وضعیت تمام زیرکانالهای شبکه اولیه یک روش تکراری ساده ارائه میدهیم و بهبود عملکرد این روش را در مقایسه با آشکارسازی مجزا که در آن آشکارسازی هر زیرکانال مستقل از بقیه است، در حالات همیار و غیر همیار مشاهده میکنیم.
In this paper, we consider the wideband spectrum sensing in which primary users use OFDM modulation. Pulse shape of each subchannel is non-ideal which results in the leakage of power among adjacent subchannels. This phenomenon makes the received energy of each subchannel (test statistic of energy detector) correlated with those of other subchannels. Therefore, in order to jointly detect the state of primary network subchannels, we propose a simple iterative method and we observe its performance improvements in comparison to the disjointed method (in which the detection of each subchannel state is independent of the detection of other s
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