Sun Yanxia, Shambare Chikomborero, Imoru OdunAyo
Department of Electrical and Electronic Engineering Science, University of Johannesburg, Johannesburg 2006, South Africa.
Department of Electrical and Computer Engineering, University of Namibia (JEDS Campus), Ongwediva 15006, Namibia.
Sensors (Basel). 2022 Aug 18;22(16):6174. doi: 10.3390/s22166174.
Quadrature phase shift keying (QPSK) is a digital modulation technique that transmits data at a constant frequency whilst varying the phases of the carrier signal. QPSK is one of the fundamental modulation schemes for orthogonal frequency division multiplexing systems (OFDM). It is a stable modulation technique with good spectral efficiency. However, during transmission, the carrier signal can undergo numerous phase changes. This creates phase ambiguity problems at the receiver end. This results in inter-symbol interference (ISI) and a high bit error rate (BER). In this paper, the wind-driven optimization was incorporated into the genetic algorithm (GA) as its population selection function. This hybrid algorithm was used to determine the phase assignments for the QPSK. The developed QPSK was implemented on an OFDM network and the message signal was recovered at more than 92% accuracy in a noisy Rayleigh fading channel and 100% accuracy in a noiseless channel. The enhancements greatly mitigated phase ambiguity and bit errors.
正交相移键控（QPSK）是一种数字调制技术，它在改变载波信号相位的同时以恒定频率传输数据。QPSK是正交频分复用系统（OFDM）的基本调制方案之一。它是一种具有良好频谱效率的稳定调制技术。然而，在传输过程中，载波信号可能会经历多次相位变化。这在接收端会产生相位模糊问题。这会导致符号间干扰（ISI）和高误码率（BER）。在本文中，将风驱动优化作为种群选择函数纳入遗传算法（GA）。这种混合算法用于确定QPSK的相位分配。所开发的QPSK在OFDM网络上实现，并且在有噪声的瑞利衰落信道中以超过92%的准确率恢复消息信号，在无噪声信道中以100%的准确率恢复。这些改进大大减轻了相位模糊和误码。
