100 likes | 113 Vues
Comment on the MATLAB Implementation of the Indoor MIMO WLAN Channel Model. Wrap Around Discontinuity. Wrap around with prime modulus used to generate fading process of each MIMO path Fading process period is product of primes
E N D
Comment on the MATLAB Implementation of the Indoor MIMO WLAN Channel Model Steven Howard, Qualcomm, Inc.
Wrap Around Discontinuity • Wrap around with prime modulus used to generate fading process of each MIMO path • Fading process period is product of primes • Wrap around reduces time coherence of MIMO channel at wrap around sample • Looks like higher Doppler • Wrap around is an implementation method, not channel characteristic Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis • Wideband MIMO Fading Channel • where t is the delay variable, tl is the delay of multipath l, L is the number of discrete multipaths, Al(t) is a time varying complex-valued Nrx x Ntx matrix describing the MIMO channel response at delay tl Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis • Use SVD to illustrate effect of wrap around on time coherence of each path Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis • Use SVD to illustrate effect of wrap around on time coherence wideband Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis Steven Howard, Qualcomm, Inc.
MIMO Channel Fading Analysis Steven Howard, Qualcomm, Inc.
Summary • Wrap around is implementation method that could effect fading simulation results • Using overlap and add processing the fading process can be extended • Does not change implementation significantly • For the specific simple Doppler filter used for the IEEE 802.11n Channel Model, a time domain implementation could be used. Steven Howard, Qualcomm, Inc.