Other Middle East and Africa Frequent Flyer Programs - doha airport

Hi to all,
I will fly next week from London to Bangkok via DOHA with Qatar airways.
Normally when I will check in in London I must get both of the boarding pass
( from London to Doha and from Doha to Bangkok) but I heard in London they give just the boarding pass to Doha and when I will be in Doha airport i must to get the other one to Bangkok. Could someone tell me someting more about the transit in Doha airport and where i can get the boarding pass to Bangkok?
Thank you !!!!!!!!!!!!!!

ive travelled this route alot in business class, have always been given the boarding card for the DOH-BKK FLIGHT at LHR. you can always pre-book seats even in economy class by calling reservations in London.