| 摘要 |
A radio communication system comprises a primary station adapted to transmit a series of data packets on a downlink channel to a secondary station. The primary station determines a property relating to the Doppler spread of the downlink channel and uses this property in the determination of suitable parameters for packet transmission. Possible properties from which an indication of the Doppler spread can be derived include the received signal to interference ratio and the transmitted power control commands. Possible parameters for packet transmission include transmission power, modulation and coding scheme, delay before retransmission of a packet received in error, and spreading factor. By determining packet transmission parameters based on uplink signal properties or on transmitted power control commands, the need for the secondary station to measure radio channel properties and signal these to the primary station is removed, thereby reducing signalling traffic and overall interference levels and extending battery life. |
