| 摘要 |
<p>A method for improving the performance of a random access communications system (10) in a variable radio environment is disclosed, whereby at least one valid set of burst signatures is used for transmission by one or more mobile stations (16, 18). Each set includes at least one signature (102) with a different signature-length (120) than the signatures in other sets. The different signature-lengths can be optimized for the operational environments involved (e.g., longer signatures for slower-moving mobile stations, and shorter signatures for high-speed mobile stations). Alternatively, at least one differentially-encoded signature is used for random access transmissions, in order to reduce the radio channel's sensitivity to large doppler spreads and frequency errors.</p> |
