摘要 |
A method and apparatus for selecting an error correction code rate in a cellular radio system. Each base station broadcasts a power product value, PP, which is its transmit power, PBT, multiplied by its desired receive power, PBR. A mobile unit determines its appropriate transmit power, PMT, by measuring its received power, PMR, and calculating PP/PMR (24). If, due to a large channel loss, the calculation result exceeds the maximum transmit power capability of the mobile unit (25), the mobile unit uses a lower code rate and adjusts the transmit power accordingly (27, 31). Three code rates, 2/3, 1/2, and 1/3, are used in the preferred embodiment in dependence on the amount of channel loss. The code rate selection can also depend on the quantity of data to be transmitted (30, 33, 34). A base station can detect the code rate by attempting to decode all code rates and choosing the best result. |