The reverse link decoder consists of an R-FCH decoder, R-SCH decoder, and R-DCCH decoder.
Note that the R-FCH decoder requires an additional operation (i.e., blind rate detection) to estimate the data rate because such information is not explicitly transmitted (note that R-FCH can use transmission at variable rates).
The data rate on the R-FCH is variable, with the ability to change on a frame-by-frame basis.
For simplicity, the term "Code Channel" is used here to represent the R-FCH, R-SCHI, R-SCH2, or R-DCCH.
(1), the mobile station sets the output power of each Code Channel (R-FCH, R-SCH1, R-SCH2 or R-DCCH), [P.sub.code], as follows:
For instance, when the mobile station is transmitting with Radio Configuration 5 (rateset 1) on the R-FCH at data rate 0, R-DCCH at data rate 0, R-SCH 1 at data rate 4, and R-SCH2 at data rate 5, Multiple_Channel_Adjustment_Gain for every Code Channel can be derived from its associated Pilot_Reference_Level as shown in Table 5.
The next step is to calculate the signal-to-noise ratio, [E.sub.b] / [N.sub.t], which is defined as the ratio of the combined received energy per bit to the effective noise power spectral density on the R-PICH, R-FCH, R-SCH1, R-SCH2, or R-DCCH at the receiver base station antenna connector .
For example, for the R-FCH, the [E.sub.b] / [N.sub.t] is given by
The pwr_fch is the output power on the R-FCH calculated from Eq.
We observe that the R-FCH performs better than the R-SCHs despite the fact that the R-FCH has smaller transmit power (P.sub.code), as indicated in Table 6.