Novel method for communications using orthogonal division duplexing of signals (ODD)
D. A. Steer, Koon Hoo Teo, B. Kirkland · 2003
As mobile radio systems expand their role in global communications, there is a need for both increased efficiency and an ability to operate in a variety of arbitrary unpaired spectrum assignments. While traditional mobile systems are mostly operated with separated transmit and receive spectrum assignments, these assignments are becoming more difficult to find for new systems among the crowded radio spectrum. Developing a radio system that is suitable for an unpaired spectrum assignment and that can also provide rapid availability of channel information for adaptive transmissions is thus a significant goal. The paper introduces a novel concept, which we refer to as orthogonal division duplexing (ODD), to address these issues. The ODD technique interleaves multiple orthogonal carriers in the same band for transmission and reception. These orthogonal carriers are produced using techniques similar to those used for OFDM. Using the same channel for both transmission and reception enables the channel conditions to be rapidly and accurately estimated by each transceiver, eliminating the delays or errors associated with traditional channel reporting techniques. The ODD transmission system is particularly well suited to multimedia high-speed mobile communications and may be designed to be adaptable to asymmetric traffic flows.