OFDM vs. SC-FDMA: Understanding the Differences

Introduction: As wireless communication technology continues to advance, different wireless communication systems are being developed to suit various applications. Two such systems that have gained popularity over the years are Orthogonal Frequency Division Multiplexing (OFDM) and Single Carrier Frequency Division Multiple Access (SC-FDMA). Both OFDM and SC-FDMA have their unique features that make them ideal for different applications. In this article, we will discuss the differences between OFDM and SC-FDMA.

OFDM: OFDM is a multi-carrier modulation scheme that has been widely used in various wireless communication systems such as Wi-Fi, digital television, and 4G LTE. In an OFDM system, the data is divided into several parallel subcarriers, each of which is modulated using a specific modulation scheme. Each subcarrier is orthogonal to the other subcarriers, meaning they are independent of each other and do not interfere with one another. This ensures that the system is resistant to multi-path fading, which is common in radio communication.

SC-FDMA: SC-FDMA, on the other hand, is a single-carrier modulation scheme that has been designed for use in the uplink of mobile communication systems such as LTE. In an SC-FDMA system, each user is assigned a specific set of subcarriers for transmission. The modulated data is then transmitted using a single carrier. Unlike OFDM, SC-FDMA does not require a guard interval between symbols, which means it can achieve higher spectral efficiency than OFDM.

Differences: The main difference between OFDM and SC-FDMA lies in their spectral efficiency and power efficiency. OFDM has a higher spectral efficiency than SC-FDMA, meaning it can transmit more data per unit of frequency. However, SC-FDMA has a higher power efficiency than OFDM, meaning it can transmit the same amount of data using less power than OFDM. This makes SC-FDMA ideal for mobile communication systems where battery life is critical.

Conclusion: In conclusion, OFDM and SC-FDMA are two different modulation schemes that are suitable for different applications. OFDM is widely used in various wireless communication systems such as Wi-Fi, digital television, and 4G LTE, while SC-FDMA is primarily used in the uplink of mobile communication systems such as LTE. Although OFDM has a higher spectral efficiency than SC-FDMA, SC-FDMA has a higher power efficiency than OFDM, making it ideal for mobile communication systems where battery life is critical.