The IEEE 802.15 Task Group 4 (802.15.4) standard is defined as a Low-Rate Wireless Personal Area Network (LR-WPAN). IEEE 802.15.4g is established specially as a physical layer (PHY) amendment to 802.15.4 for Smart Utility Network (SUN) applications such as the smart gird system. The low-rate design emphasis enables low power and simple hardware implementation. The intent of the amendment is to offer a global standard that eases very large- scale process control applications such as smart grids and smart meters. SUN can be fielded with millions of fixed end point users; by using IEEE 802.15.4g, it's able to support large, geographically diverse networks with very tiny infrastructure. Simple, narrowband modulation schemes like Offset Quadrature Phase Shift Keying (OQPSK) and Multi Rate Multi Regional-OQPSK (MR-OQPSK) are preferred to obtain reduced levels of power consumption. Additionally, the IEEE 802.15.4g standard is optimized for low cost, low rate and low power and is suitable for very short distance applications. This thesis studies the IEEE 802.15.4 and IEEE802.15.4g standard to learn the physical layer requirements of the modulator and demodulator. A set of design configurations is considered to select a design that cost-effectively meets the standards. The selected configuration will be simulated in MATLAB to verify performance of the design and its susceptibility to noise.