Bruce Wayne is aging and he's tired of being Batman--an angry vigilante, but a symbol of hope. Before John Blake, there was no other contender to take Batman's mantle and legacy and keep the city of Gotham safe. At first he wanted to be Batman. But then Rachael died, Bruce lost any aspect of a personal life and happy future, and he -had- to be Batman when Bane returned. He wanted to die and give Gotham everything he possessed.
But then he meets Selina Kyle and John Blake--both offer him an easy escape. Alfred had told him, "I hoped you'd never return. Because I knew there was nothing for you here but pain and suffering. And I wanted more for you than that." Bruce can never have a 'happily ever after' in Gotham City--a city carrying so many painful memories for him. So he fakes his death so that he can be 'reborn' again (that's the theme of the film--hope and rebirth).
And to the person that suggests the connection between Wayne and Batman would be obvious-- Bruce Wayne went missing for four months. When he reappears (before -very- few people), he's being lead away to Bane by Selena and Bane's henchmen so that he can be tried and executed. Everyone that sees him will assume Bane murdered him.
Batman, on the other hand, is seen by quite a few people in broad daylight. He's seen driving the Bat, which they see explode. After Bruce Wayne has already been 'executed'.