OFDM‐based adaptive modulation systems with a multilevel transmit power control for high‐bit‐rate transmission
OFDM‐based adaptive modulation systems with a multilevel transmit power control for high‐bit‐rate transmission
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基于 OFDM 的自适应调制系统，具有用于高比特率传输的多级发射功率控制
DOI：
10.1002/ecja.10000
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
N. Morinaga
中科院分区：
文献类型：
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作者：
T. Yoshiki;S. Sampei;N. Morinaga
在OFDM（正交频分复用）自适应调制系统中，自适应地控制每个子载波的调制方法。它是一种用于宽带传输的有用系统，因为可以在有限的带宽内实现高传输速率。还有一种通过控制来抑制发射功率的方法，以应对宽带系统中不断增加的发射功率。然而，在频率选择性衰落环境中出现问题，其中每个子载波的接收功率随时间变化，这导致不必要的发送功率消耗。本文提出了应用多级发射功率控制，其中发射功率被独立地控制为每个子载波，使得每个调制方法满足BER要求为每个子载波选择的调制电平的数量。在所提出的系统中，实现所需质量后剩余的发射功率被有效地分配给其他子载波。然后，通过选择更大数目的调制电平，在有限的频带中实现更高的传输速率。通过计算机仿真对该系统的传输性能进行了评估，验证了该系统的传输速率得到了很大的提高。© 2002 Wiley Periodicals，Inc. Electron Comm Jpn Pt 1，85（11）：34-43，2002;在线发表于Wiley InterScience（www.interscience.wiley.com）。DOI 10.1002/ecja.10000
In the OFDM (orthogonal frequency division multiplexing) adaptive modulation system, the method of modulation of each subcarrier is adaptively controlled. It is a useful system for wide-band transmission, since a high transmission rate can be realized in a limited bandwidth. There is also a method that suppresses the transmit power by control, in order to handle increasing transmit power in a wide-band system. A problem arises, however, in a frequency-selective fading environment, in which the received power of each subcarrier varies with time, which results in unnecessary transmit power consumption. This paper proposes to apply multilevel transmit power control in which the transmit power is independently controlled for each subcarrier, so that each modulation method satisfies the BER requirement for the number of modulation levels selected for each subcarrier. In the proposed system, the transmit power which remains after achieving the required quality is effectively assigned to other subcarriers. Then, by selecting a larger number of modulation levels, a higher transmission rate is realized in a limited band. The transmission performance of the proposed system is evaluated by computer simulation, and it is verified that the transmission rate is greatly improved. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(11): 34–43, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10000