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 fading.

#### Author: Yasir Ahmed (aka John)

More than 20 years of experience in various organizations in Pakistan, USA and Europe. Worked as Research Assistant within Mobile and Portable Radio Group (MPRG) of Virginia Tech and was one of the first researchers to propose Space Time Block Codes for eight transmit antennas. The collaboration with MPRG continued even after graduating with an MSEE degree and has resulted in 12 research publications and a book on Wireless Communications. Worked for Qualcomm USA as an Engineer with the key role of performance and conformance testing of UMTS modems. Qualcomm is the inventor of CDMA technology and owns patents critical to the 5G and 4G standards.

Hello ,

How we can calculate the inter-site interference in LTE for a user on the edge cell ? if we consider only interference from the first tier cells only , if we have a target bit rate for cell edge user ,we need to calculate the noise and interference to get SINR and to calculate the coverage right?

Thanks

Thank you Shaokn for pointing that out!

John

Where is log2 ?