Spectrum Efficiency of Lognormal Fading Channels under Different Adaptation Policies with MRC Diversity

We consider a Single Input Multiple Output (SIMO) system in the presence of Lognormal Multipath Fading (LMF) channel. We study Shannon capacity of different adaptive transmission policies in conjunction with diversity combining techniques and provide an upper bound on spectral efficiency using these techniques. We obtain closed-form expressions for spectrum efficiency in a Lognormal fading channel under these adaptation policies: (i) Optimal Power and Rate Adaptation (OPRA), and (ii) Truncated channel Inversion with Fixed Rate (TIFR). Numerical results show that there is an increase in spectrum efficiency when these adaptation policies are used in conjunction with diversity combining techniques.