Performance and capacity evaluations of CDMA mobile radio systems-forward link analysis

Performance and capacity of CDMA for mobile radio applications have been studied in detail by extensive computer simulation of large service area consisting of 19 hexagonal cells. Major results of the study are as follows: (i) interference initiating from the pilot tone reduces the 1st percentile of the speech channel´s C/I, which offsets the improvements resulting from coherent combining capabilities; for the 10th percentile of C/I distribution, overall improvements resulting from the pilot transmission are 1 dB. (ii) With a pilot channel transmission in the forward link, the slope of the “C/I percentile” versus “number of active mobiles” curve is -2 dB/octave. (iii) The required dynamic range for 1st and 10th percentiles of the C/I distribution are, respectively, 10 dB and 5 dB. (iv) With a 2 dB standard deviation for power control, capacity reduces to 20% of its ideal value. (v) A dynamic range of 12 dB for the transmission power of the base is adequate. (vi) Capacity increases drastically by increasing path loss of transmission