A study of novel OFDM transmission schemes for use in indoor environments

Multicarrier techniques are being considered in various applications. One particular multicarrier modulation format, orthogonal frequency division multiplexing (OFDM), has been investigated for use in terrestrial digital radio and digital television. Although OFDM systems can provide considerable immunity to the effects of multipath propagation, in general they are highly sensitive to the effects of distortion caused by transceiver imperfections. We detail some possible simple OFDM alternatives to present generation digital cordless systems, using only a small number of subchannels. In this way it is shown that systems can be developed with low sensitivity to distortion. For comparison purposes the frame structure of the Digital European Cordless Telecommunications (DECT) system has been used, although the work is intended to be applicable in other areas. In particular adaption of the techniques discussed is possible for use in high bit rate systems, such as wireless local area networks (WLAN). The systems presented may also be modified for use in US licensed/unlicensed PCS applications, where systems based around the DECT standard have been proposed