摘要 |
<p>A wireless local area network system comprises an ATM switch (10) coupled to an access point (12) having a transceiver and a plurality of mobile terminals (14) each having a transceiver. The transceivers operate in accordance with an Orthogonal Frequency-Division Multiplexing (OFDM) transmission scheme having a plurality of channels. In response to the access point (12) polling the mobile terminals (14) enquiring if they want a time slot in the next down-link frame, those mobile terminals wanting a time slot transmit an E-burst on selected ones of the plurality of channels whose phases are selected to minimise the transmitted peak to mean envelope power. Optionally the E-burst can be modulated to provide a limited amount of signalling information.</p> |