Performance evaluation of subcarrier hopping multiple access in wireless LAN scenarios

We consider a new orthogonal frequency-division multiplexing (OFDM)-based uplink multiple access system called subcarrier hopping multiple access (SHMA) targeting real-time wireless communications such as motion controls of vehicles and machines. By applying the super-orthogonal convolutional codes (SOCC) as a channel code with subcarrier hopping, it can achieve reliable communications due to the frequency diversity and coding gain without increasing decoding latency. In this work, we attempt to evaluate its system level performance according to the specifications and channel models of the IEEE 802.11n standard, aiming at its use for WiFi compatible environment. In particular, the frame error rate (FER) performance comparison reveals that the proposed SHMA can achieve higher reliability than the IEEE 802.11n standard at the cost of reduced data rate, which is still suitable for the purpose of motion control applications. The proposed SHMA system exploits Golay sequences as the outputs of SOCC in order to suppress the peak power of OFDM signals. We also evaluate the gain provided by this low peak power property taking into account the power amplifier (PA) efficiency. Finally, we address how these gains contribute to the enhancement of the transmission range over the conventional WiFi standard for a given amount of average power at the transmitter.