US Patent 7558238 Hybrid multiple access waveform, method, and apparatus

A method for partitioning communication resource among multiple users partitions a portion of an available communication resource into a series of time-frequency slots, and allows multiple users to transmit in one of at least two available modes within a time-frequency slot. Preferably, one mode is time division of the time-frequency slot into time sub-slots, and another mode is code division of the time-frequency slot according to different spreading codes that spread an individual user's signal only within the subject time-frequency slot. Further details as to pilot signals, guard intervals, and payloads are described.