Electrical Engineering Department, Faculty of Engineering, King Khalid University, Abha 61411, KSA.
Electrical Engineering Department, Faculty of Engineering, Aswan University, Aswan 81528, Egypt.
Sensors (Basel). 2018 Dec 11;18(12):4382. doi: 10.3390/s18124382.
Due to the Internet of Things (IoT) requirements for a high-density network with low-cost and low-power physical (PHY) layer design, the low-power budget transceiver systems have drawn momentous attention lately owing to their superior performance enhancement in both energy efficiency and hardware complexity reduction. As the power budget of the classical transceivers is envisioned by using inefficient linear power amplifiers (PAs) at the transmitter (TX) side and by applying high-resolution analog to digital converters (ADCs) at the receiver (RX) side, the transceiver architectures with low-cost PHY layer design (i.e., nonlinear PA at the TX and one-bit ADC at the RX) are mandated to cope with the vast IoT applications. Therefore, in this paper, we propose the orthogonal shaping pulses minimum shift keying (OSP-MSK) as a multiple-input multiple-output (MIMO) modulation/demodulation scheme in order to design the low-cost transceiver architectures associated with the IoT devices. The OSP-MSK fulfills a low-power budget by using constant envelope modulation (CEM) techniques at the TX side, and by applying a low-resolution one-bit ADC at the RX side. Furthermore, the OSP-MSK provides a higher spectral efficiency compared to the recently introduced MIMO-CEM with the one-bit ADC. In this context, the orthogonality between the in-phase and quadrature-phase components of the OSP are exploited to increase the number of transmitted bits per symbol (bps) without the need for extra bandwidth. The performance of the proposed scheme is investigated analytically and via Monte Carlo simulations. For the mathematical analysis, we derive closed-form expressions for assessing the average bit error rate (ABER) performance of the OSP-MSK modulation in conjunction with Rayleigh and Nakagami-m fading channels. Moreover, a closed-form expression for evaluating the power spectral density (PSD) of the proposed scheme is obtained as well. The simulation results corroborate the potency of the conducted analysis by revealing a high consistency with the obtained analytical formulas.
由于物联网 (IoT) 需要具有低成本和低功耗物理 (PHY) 层设计的高密度网络，因此具有低功耗预算的收发器系统最近引起了人们的极大关注，因为它们在能量效率和硬件复杂性降低方面具有卓越的性能提升。由于经典收发器的功率预算是通过在发射端 (TX) 使用效率低下的线性功率放大器 (PA) 和在接收端 (RX) 使用高分辨率模数转换器 (ADC) 来设想的，因此具有低成本 PHY 层设计（即在 TX 处使用非线性 PA 和在 RX 处使用一位 ADC）的收发器架构需要应对广阔的物联网应用。因此，在本文中，我们提出了正交成形脉冲最小频移键控 (OSP-MSK) 作为多输入多输出 (MIMO) 调制/解调方案，以便为与物联网设备相关的低成本收发器架构进行设计。OSP-MSK 通过在 TX 端使用恒包络调制 (CEM) 技术，以及在 RX 端使用低分辨率的一位 ADC，实现了低功耗预算。此外，与最近提出的具有一位 ADC 的 MIMO-CEM 相比，OSP-MSK 提供了更高的频谱效率。在这种情况下，利用 OSP 的同相和正交分量之间的正交性来增加每个符号的传输比特数 (bps)，而无需额外的带宽。通过分析和蒙特卡罗模拟来研究所提出方案的性能。对于数学分析，我们推导出了用于评估 OSP-MSK 调制在瑞利和 Nakagami-m 衰落信道下的平均误比特率 (ABER) 性能的闭式表达式。此外，还获得了评估所提出方案的功率谱密度 (PSD) 的闭式表达式。仿真结果通过揭示与获得的分析公式的高度一致性，证实了所进行的分析的有效性。
