Tag: Throughput

Channel Capacity, LTE

Average Cell Throughput Calculations for LTE

Average Cell Throughput requires the following simulation results • Average SINR distribution table (system level result), which provides the SINR probability • Average throughput or spectral efficiency versus average SINR table (link level result) For urban channel model and a fixed inter-site distance of 1732m,downlink throughput for LTE for different values of SINR is shown below. MCS vs SINR Average Cell Throughput=Σ(Pi*Ri) where Pi=Probability of occurrence of a specific SINR value at cell edge obtained using simulations Ri=Average throughput corresponding to SINR range Let us consider the following distribution for the SINR at the cell edge: P1=0.5 (SINR=1.50-3.50 dB) P2=0.25 […]

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Capacity, LTE

LTE Data Rate Calculation

Peak LTE data rate can be calculated using the following parameters: 1 Time-slot=0.5 ms (i.e 1 Sub-frame = 1 ms) 1 Time-slot=7 Modulation Symbols (when normal CP length is used) 1 Modulation Symbol=6 bits; if 64 QAM is used as modulation scheme Data rate for a single carrier=Number of symbols per time slot*Bits per symbol/Duration of a time slot=7*6/0.5e-3=84kbps If 1200 carriers (100RBs) are used then the aggregated throughput would be=1200*84kbps=100.8Mbps If 4×4 MIMO is used then the capacity would increase four fold to=403.2Mbps With 3/4 channel coding the data rate would be reduced to=302.4Mbps Note: 1. A Resource Block […]

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Capacity, LTE

Shannon Capacity of LTE (Effective)

In the previous post we calculated the Shannon Capacity of LTE as a function of bandwidth. We now calculate the capacity as a function of SNR (bandwidth fixed at 20MHz and signal power varied). We also use the concept of effective bandwidth to get a more realistic estimate of the capacity. The modified Shannon Capacity formula is given as: C=B_eff*log2(1+SNR) where B_eff=Bandwidth*eff1*eff2*eff3*eff4 eff1=0.9=due to adjacent channel leakage ratio and practical filter issues eff2=0.93=due to cyclic prefix eff3=0.94=due to pilot assisted channel estimation eff4=0.715=due to signalling overhead B_eff=0.57*B Therefore C=0.57*B*log2(1+SNR) Note: This is the capacity in a SISO channel with no […]

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