| 摘要 |
The traffic load between a busy cell and adjacent cells with spare capacity is optimized by allocating the transmission of delay unconstrained packet data, such as e-mail, to an adjacent cell. To maintain C/I ratio for the call, the transmitting terminal increases the energy per bit by, for example, reducing modulation rate (ie data rate), using modulation with fewer levels (such as 16 QAM to QPSK), increasing FEC overhead and/or spectrum spreading factor (increased redundancy), or increasing the interleaving depth (spreading interference more widely). As the nominal edge of cell will have been effectively extended, the mobile terminals transmitting data may be closer than normal to a remote cell which is re-using the same frequency. The terminal transmitting data therefore maintains or reduces power to avoid co-channel interference. Reducing power requires the addition of still further reduction in data rate in order to maintain the required energy per bit/symbol at the serving base station. |
