为了在被剪波的正交频分复用系统中补偿幅度衰减和缓解剪波噪声,提高系统的误比特性能,提出了一个新的剪波比估计算法.考虑正交频分复用系统中的导频子载波一般是低阶相移键控调制符号,因此这些导频子载波的解调不受幅度衰减影响但是它的误比特率却是剪波比参数的函数.通过推导导频子载波误比特率的闭合表达式,并使用该关系和解一个关于剪波比的方程给出了估计的剪波比.两种评估方法被引入以对估计准确性进行评估.两种评估仿真结果表明,在多径静态衰落信道环境下,即使信噪比很低,提出的算法也优于当前现有的算法.%A new approach was proposed for clipping ratio (CR) estimation when amplitude attenuation should be compensated and clipping noise mitigated to improve the bit-error rate (BER) performance of orthogonal frequency division multiplexing (OFDM) system wherein the clipping method was adopted to reduce the high peak-to-average power ratio (PAPR).It was noted that the pilot subcarriers were modulated by phase-shift keying (PSK) scheme in OFDM communication.Therefore,the demodulation of the pilot subcarrier was independent of the amplitude attenuation caused by clipping but its corresponding BER was the funtion of the CR parameter.The closed-form of the BER performance of pilot subcarriers was derived.By exploiting the relationship,an estimate of CR was obtained by solving an equation with respect to CR parameter.Two evaluation rules were employed to evaluate the estimation accuracy of the proposed method.Under the static multipath channel condition, both evaluation results demonstrate that the proposed algorithm is superior to the previous algorithm even for very low signal-to-noise power ratio (SNR).
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