CP-OFDMA

Cyclic-Prefix Orthogonal Frequency Division Multiple Access (CP-OFDMA) is a digital multi-carrier modulation scheme utilised in wireless communications to prevent intersymbol interference (ISI). This technique employs a cyclic prefix to preserve the orthogonality of transmitted signals, thus enhancing the robustness of the system against multipath fading and delay spread. In CP-OFDMA, the data stream is divided into several parallel sub-streams, each of which is modulated using a separate subcarrier. These subcarriers are orthogonal to each other, meaning they can be separated at the receiver without causing interference. The addition of a cyclic prefix involves copying a portion of the end of the OFDM symbol and appending it to the start. This prefix acts as a buffer against multipath interference and ISI, allowing for more reliable data transmission. CP-OFDMA is widely used in various wireless communication standards, including 4G and 5G, due to its high spectral efficiency, flexibility, and ability to handle high data rates.