The coded orthogonal frequency division multiplexing (COFDM) technique, and its application to digital radio broadcasting towards mobile receivers

A system which is able to broadcast at high data rates in a selective Rayleigh channel is presented. This technique combines an orthogonal frequency division multiplexing technique and a convolutional coding scheme associated with a Viterbi decoding algorithm. This system is able to benefit from wideband transmission by employing the information contained in all the echoes of the multipath channel while having a very good spectral efficiency and a low computational complexity. The authors present the theoretical principles of the system. They describe the realization of a complete COFDM (coded orthogonal frequency division multiplexing) system, designed within the framework of the DAB (digital audio broadcasting) EUREKA 147 project, which is able to broadcast at 5.6 Mb/s in a bandwidth of 7 MHz. At present, this rate corresponds to 16 high-quality stereophonic programs. Network aspects are pointed out as far as the introduction of a new radio broadcasting service is concerned