COFDMbased

COFDMbased is a term used to describe systems that implement coded orthogonal frequency-division multiplexing, combining OFDM modulation with forward error correction coding to improve robustness in multipath and fading channels. It is used to characterize a family of digital communication schemes and standards built around this approach.

In COFDMbased systems, the available spectrum is divided into many orthogonal subcarriers. Data is mapped onto these subcarriers, and a channel coding scheme—such as convolutional codes, LDPC, or turbo codes—adds redundancy for error correction. The data stream is interleaved to spread errors caused by fading, and a cyclic prefix or guard interval mitigates inter-symbol interference. At the receiver, channel estimation and equalization are used to recover the transmitted symbols, with the error-correcting code providing additional protection against noise and interference.

Typical applications of COFDMbased technology include digital broadcasting and multimedia delivery (for example, DVB-T and DVB-T2), digital radio standards (such as DAB/DAB+, and related mobile broadcasting systems), as well as certain wireless and powerline communication systems that require robust performance in multipath environments. The approach is valued for its scalability, spectral efficiency, and compatibility with high data-rate services.

Advantages of COFDMbased designs include strong resilience to multipath propagation, flexible data rates by adjusting subcarrier constellations, and the ability to support wide bandwidths. Limitations involve higher computational complexity, Doppler sensitivity, overhead from coding and guard intervals, and the need for accurate synchronization and channel state information. See also Orthogonal frequency-division multiplexing and Channel coding.