It sounds like you have a Section 32 Buyout policy, which it appears to be if it is paying you a revalued Guaranteed Minimum Pension.
Any GMP which you earned before 6th April 1988 will recieve increases but these will be paid by the State. So you will receive future increases on this prt of your pension after State Pension Age which reflect increases in inflation.
Friends Life will be able to confirm this if you have any doubt.
Hope this helps?