Single-RF Diversity Receiver for OFDM System Using ESPAR Antenna with Alternate Direction
Single-RF Diversity Receiver for OFDM System Using ESPAR Antenna with Alternate Direction
复制标题
使用 ESPAR 交替方向天线的 OFDM 系统单射频分集接收机
DOI：
10.37936/ecti-cit.201261.54325
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发表时间：
1970
期刊：
影响因子：
--
通讯作者：
M. Okada
中科院分区：
文献类型：
--
作者：
S. Tsukamoto;M. Okada
提出了一种基于单射频分集的正交频分复用（OFDM）接收机方案，该方案采用了方向以OFDM符号速率交替变化的电子可控无源阵列辐射器（ESPAR）天线，OFDM因其在严重时散多径传播信道中的宽带无线传输能力而被广泛应用于移动的通信系统。然而，OFDM并不能有效地缓解衰落带来的性能下降，分集技术是解决这一问题的有效技术。虽然最大比合并分集是最有效的技术，但它需要与天线相同数量的RF前端电路和模数转换器（ADC）。基于ESPAR天线的分集技术虽然只需要一个RF和ADC，但收敛速度不够快，无法跟踪信道状态的快速变化，而且在频率选择性信道中效率不高。本文提出了一种基于ESPAR天线的OFDM分集方案。该方案能够在频率选择性衰落环境中获得分集增益，避免了传统ESPAR天线技术收敛速度慢的问题。计算机仿真结果表明，该方案在频率选择性衰落信道中具有分集增益。
This paper presents a single-RF diversity scheme for orthogonal frequency division multiplexing (OFDM) receiver using Electronically Steerable Passive Array Radiator (ESPAR) antenna whose direction changes alternately at the OFDM symbol rate. OFDM is widely used for mobile communication systems because of its broadband wireless transmission capability in a severe time dispersive multipath propagation channel. OFDM is, however, not efficient for mitigating the performance degradation due to fading. Diversity is an efficient technique for solving this problem. Although maximal ratio combining diversity is the most efficient technique, it requires the same number of RF front-end circuitry and analog-todigital converters (ADC) as antennas. Although ESPAR antenna-based diversity technique requires only a single-RF and ADC, the convergence is not fast enough to track fast variation of the channel state. Furthermore, it is not efficient in a frequency selective channel. In this paper, we propose a new OFDM diversity scheme using ESPAR antenna. The proposed scheme is capable of obtaining the diversity gain in a frequency selective fading environment and avoids the slow convergence rate problem in the conventional technique using ESPAR antenna. Computer simulation results show that the proposed scheme gives diversity gain in a frequency selective fading channel.