I want to cover the 360 deg range with eight sectoral anten

hello every one:

my problem is..

I want to cover the 360 deg range with eight sectoral antennas of 30 deg 3db beamwidth....if I use the normal configuration(distribute the antennas around a circule with spacing of 45 deg ) this will result gaps in the covering area...how can I destribute them...to acheive the total covering...?

thanks...