BIT SIGNIFICANCE SELECTIVE FREQUENCY DIVERSITY TRANSMISSION

This paper proposes a frequency diversity transmission scheme that obt ains a frequency diversity gain and does not degrade spectrum efficien cy; it utilizes multiple carrier frequencies alternately, not simultan eously. This scheme improves the bit error rate (BER) of significant i nformation bits by sacrificing that of insignificant bits in fading ch annels. Simulation results show that the error floor of significant in formation bits is reduced to less than 1/5 while that of insignificant bits is doubled. They also show that the proposed scheme improves the received 4-bit ADPCM voice signal-to-noise ratio (SNR) by approximate ly 4 dB even when the frequency correlation is 0.5.