Pa Pb in LTE and its impact on User Throughput
Downlink signals are made up of many different components. For example, Reference Signal, PDCCH, PDSCH etc. The RS power and the SCH powers are key RF optimization parameters that influences the cell coverage. It is set according to the cell size. The higher the setting, the larger the cell coverage on the downlink, but leaves smaller power headroom available for other downlink signals and channels. The relation between RS power and power on PDSCH symbols (includes type A and type B symbols), has to be defined and reported to the UE, in order for the UE to demodulate 16QAM and 64QAM.1 PDSCH type A symbols has only PDSCH RE’s, PDSCH type B symbols has mixed RS and PDSCH REs. Parameter PA sets the power of PDSCH type A RE relative to cell‐specific RS, PB sets the power relation between PDSCH type B RE, and PDSCH type A RE (ρB/ρA in 3GPP). The ratio of PDSCH EPRE to cell‐specific RS EPRE among PDSCH REs for each OFDM symbol is denoted by either ρA or ρB a...