OFDM系統(tǒng)功率和比特分配算法研究
Bit and Power Allocation Algorithm for OFDM System
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摘要: 該文研究OFDM系統(tǒng)在總功率和誤比特率限定下最大化傳輸速率的問(wèn)題,并且考慮實(shí)際系統(tǒng)中整數(shù)比特的限制,提出基于灌水法則的兩種比特分配算法--改進(jìn)的貪婪算法和對(duì)分灌水線搜索法,兩種算法在計(jì)算復(fù)雜度上分別比貪婪算法和迭代灌水線搜索法小.仿真結(jié)果表明,改進(jìn)的貪婪算法在性能上十分接近于貪婪算法,但是計(jì)算復(fù)雜度僅是貪婪算法的10%～30%,而對(duì)分灌水線搜索法在信噪比大于10dB的時(shí)候只要5～7次迭代便可以達(dá)到與貪婪算法只相差0.5%的性能.
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關(guān)鍵詞:
- 比特分配; OFDM; 貪婪算法; 灌水法則; 對(duì)分搜索
Abstract: The maximization of data rate under the constraint of total transmit power and bit error rate is a considerable issue in OFDM system. Recognizing that the number of bits on each subcarrier must be a discrete number for real systems, this paper proposed two bit allocation algorithms which are modified greedy algorithm and water filling level binary searching algorithm. Simulation results show that the complexity of modified greedy algorithm is 10% of that of greedy algorithm and 5-7 iterations are enough for 0.5% data rate loss when SNR is above 10dB. -
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