The Relation Of Lte Cell Max Transmit Power With Pa Pb And Rs Power_djf 404v1d

The relation of LTE cell max transmit power with PA PB and RS power Basic conception/definition 1) Cell specific RS EPRE (EPRE rs)：The downlink reference-signal transmit power is defined as the linear average over the power contributions (in [W]) of all resource elements that carry cell-specific reference signals within the operating system bandwidth. 2) ρa：PDSCH EPRE(type A symbol (type A symbol, refers to symbol 1，2，3，5，6 in normal frame type, where in the symbols only PDSCH is carried))/Cell specific RS EPRE 3) ρb： PDSCH EPRE(type B symbol (type B symbol refers to symbol 0，4 in normal frame type, where in these symbols both PDSCH and RS are carried))/Cell specific RS EPRE 4) PB in configurable, it is a cell specific parameter, the value can be 0,1,2,3, PB decides the relationship of ρa and ρb, table 5.2-1 5) PA is configurable, it is a UE specific parameter, the value can be -3、-4.77、-6、—-1.77、 0、 1、2、3. Unit is Db。 In the protocal the difination of PA is: ρa is equal to Δpower-offsetPA[dB] in most case Δpower-offset=0, (except in case of multi MIMO) ρa =PA

The cell Max transmit power calculation is based on the configured PA, but the PA is a specific parameter, it could be dynamic changed for different s, but the system will guarantee the total transmit power of the cell not exceeding the maximum.

Discussion on LTE max transmit power

1) Definition of Cell max transmit power as blow: The formula below is applicable for ERAN3.0 and later version, in earlier version the max transmit power only take the type A symbol, the first part of the formula. Max. Output Cell Power (per antenna port) = MAX{ Max transmit power of one Type A symbol, Max transmit power of one Type B symbol } -

Max transmit power of one Type A symbol=Configured TypeA data RE power（mW） * Number of REs in one type A symbol(in one RB the number is 12, in 20Mhz bandwith the number is 1200). Max transmit power of one Type B symbol=Configured pilot power（mW） *Number of the pilot symbol in one Type B symbol (in 2/4 antenna port case, the number of pilot symbol is 2 in one RB, in calculation should consider the bandwidth)+ according to the configuration calculated data RE power in Type B symbol * the numbers of the data RE in one Type B symbol. In the formula:

- Configured TypeA data RE power（mW）= Configured pilot power（mW） * dBtoLin （configured PA） - according to the configuration calculated data RE power in Type B symbol= Max transmit power of one Type A symbol（mW） * (decided by the configured PB value)

We can also express it in the following way: Max. Output Cell Power (per antenna port) = MAX{ Max transmit power of one Type A symbol, Max transmit power of one Type B symbol }

In case two or more TX antenna ports: Max transmit power of one Type A symbol (in dBm) =10 * log [EPRE rs (mw) * Pa (linear) * 12 * Nrb] Max transmit power of one Type B symbol (in dBm) = 10 * log [(EPRE rs (mw) * Pa (linear) *

(linear) *

8 * Nrb) + (EPRE rs (mw) * 2 * Nrb)]

In case one TX antenna port: Max transmit power of one Type A symbol (in dBm) =10 * log [EPRE rs (mw) * Pa (linear) * 12 * Nrb] Max transmit power of one Type B symbol (in dBm) = 10 * log [(EPRE rs (mw) * Pa (linear) *

(linear) *

10 * Nrb) + (EPRE rs (mw) * 2 * Nrb)]

Let us see several calculation examples for 1T1R: Example 1: 20 Mhz, 100 RB, EPRErs = 15.2 dBm,Pb=1 Pa = 0, Max. Ouput Cell Power (per antenna port) = MAX{ Max transmit power of one Type A symbol, Max transmit power of one Type B symbol } Where: Max transmit power of one Type A symbol (in dBm) =10 * log [EPRE rs (mw) * Pa (linear) * 12 * Nrb] = 10 * log (33,11 * 1 * 1200) = 46 dBm Max transmit power of one Type B symbol (in dBm) = 10 * log [(EPRE rs (mw) * Pa (linear) * (linear) * 10 * Nrb) + (EPRE rs (mw) * 2 * Nrb)] = 10 * log [(33,11 * 1 * 4/5 * 1000) + (33,11 * 200)] = 45.2 dBm

Max. Ouput Cell Power (per antenna port) = MAX{ 46 dBm, 45.2 dBm } = 46 dBm

Example 2: 20 Mhz, 100 RB, EPRErs = 18.2 dBm, Pb=1, Pa = -3 dB Max. Ouput Cell Power (per antenna port) = MAX{ Max transmit power of one Type A symbol, Max transmit power of one Type B symbol } Where: Max transmit power of one Type A symbol (in dBm) =10 * log [EPRE rs (mw) * Pa (linear) * 12 * Nrb] = 10 * log (66,22 * 1/2 * 1200) = 46 dBm Max transmit power of one Type B symbol (in dBm) = 10 * log [(EPRE rs (mw) * Pa (linear) * (linear) * 10 * Nrb) + (EPRE rs (mw) * 2 * Nrb)] = 10 * log [(66,22 * 1/2 * 4/5 * 1000) + (66,22 * 200)] = 46 dBm

Max. Ouput Cell Power (per antenna port) = MAX{ 46 dBm, 46 dBm } = 46 dBm

Example 3: 20 Mhz, 100 RB, EPRErs = 15.2 dBm, Pb=0, Pa = 0 dB Max. Ouput Cell Power (per antenna port) = MAX{ Max transmit power of one Type A symbol, Max transmit power of one Type B symbol } Where:

Max transmit power of one Type A symbol (in dBm) =10 * log [EPRE rs (mw) * Pa (linear) * 12 * Nrb] = 10 * log (33,11 * 1 * 1200) = 46 dBm Max transmit power of one Type B symbol (in dBm) = 10 * log [(EPRE rs (mw) * Pa (linear) * (linear) * 10 * Nrb) + (EPRE rs (mw) * 2 * Nrb)] = 10 * log [(33,11 * 1 * 1 * 1000) + (33,11 * 200)] = 46 dBm

Max. Ouput Cell Power (per antenna port) = MAX{ 46 dBm, 46 dBm } = 46 dBm 2) The Maximum. transmit power can be obtained by executing MML COMMAND  DSP CELL the result is the same as Max. Output Cell Power (per antenna port) calculated in Step 1) in this email.

3) Maximum Output Cell Power of the cell is always calculated dynamically based on EPRE RS, Pa, Pb and Cell Bandwidth following formula provided in step 1) With exceptions When RRU Power lock is set, the max power of the RRU will accordingly limited by the locked Max Power (the command is LOC RRUTC. 4) how it is done the RS Power Boosting in 1T1R cells and how it is provided the extra power used to boost the RS in symbol 0 and symbol 4 of the OFDMA frame in that scenario (1T1R)? In case of 1T1R Huawei do not recommend to have power boosting, PA-PB configure to 00