| Popis: |
Two modulation schemes, namely Single-Carrier (SC), Orthogonal Frequency Division Multiplexing (OFDM), are widely recommended in the currently undergoing 60 GHz millimeter-wave standard draft IEEE 802.11ad. Low Density Parity Check (LDPC) code is also adopted in the sense of its much better performance in correcting errors comparing the other FEC codes. However, OFDM system is extremely vulnerable to the nonlinear distortion caused by the 60 GHz power amplifier (PA) nonlinear property as a consequence of its significant peak to average ratio (PAPR). In this article, we utilize a promising companding transform (CT) algorithm which is also combined with predistortion scheme, in order to combat the PA nonlinear distortion. Experimental results demonstrate our proposed scheme exhibits much better performance in resisting PA nonlinear distortion, and the new scheme is also easy to implement in practical design of 60 GHz millimeter-wave systems. |
