Abstract:A transmission scheme is proposed based on multi-input multi-output orthogonal frequency-division multiplexing (OFDM) for underwater acoustic multimedia (UWAM) communication. The proposed scheme integrates direct mapping and space-time block code strategies, a power assignment mechanism, OFDM, adaptive modulation, and unequal error protection in a UWAM system. The proposed UWAM system employs high power, low speed modulation, with schemes providing significant error protection for transmission of sensor data messages requiring a stringent bit-error rate (BER). In contrast, low power, high speed modulation schemes with reduced error protection are provided for messages that can tolerate a high BER, such as image and audio signals. Simulation results show that the proposed scheme not only fulfils the quality of services requirements of a UWAM system, but also maximizes transmission bit rates or minimizes transmission power requirements.