MODULATION METHOD FOR TRANSMITTER

摘要

In a wireless communication system, the constellation mapping scheme employ ed may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot i n different consecutive frames. In other words, several constellation mapping schemes ar e available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mappi ng used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known à priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.