This doesn't even sound like it has anything to do with Lawful Good. A code of honor has nothing to do with alignment. All alignments can have codes of honor. (And questions of morality are always a sticky area, since it's not uncommon for people to view the exact same action in a different moral light. For example, in addition to varied other reasons, people are for or against the death penalty in the real world based on moral grounds.)
Lawful Evil people can have codes of honor that prevent the slaying of sleeping foes. Lawful Good people can have codes that require them to take advantage of their evil foes being asleep to kill them. In either case, it doesn't change the alignment of the person.
Good does NOT mean dumb. It does NOT mean giving up tactical advantages. SOME codes of honor might, though.
The problem doesn't seem to be your alignment. (Though I'm not sure if someone who actively works against the group they are with could be considered lawful good...) And before you object to that, remember that taking prisoners, in almost all cases, puts the party more at risk. This is fine when the party agrees to that risk, of course, but when most of them don't you are in the wrong.
Playing LG and following a code of honor are different things. If your code of honor requires you to not harm sleeping foes, that's perfectly fine in a code of honor. If it requires you to take every tactical advantage to kill your evil foes, that's fine as well.
Heck, look at some of the examples given. Your code, as represented by you, would go directly against a couple of Pathfinder's Paladin codes in many situations. You aren't wanting 'compromise' ... you are wanting them to follow YOUR code, instead of theirs. That's not compromise. Compromise would be you accepting they will do things you won't like. And you will do things they won't like, but you will both keep doing them, because that's just how you are.
It seems to me, you have 3 viable options.
You can examine your code, in the light of the 'real world' of the game, and modify it.
You can work WITH the party, understanding, as mentioned above, that you simply won't always agree. Just make sure they understand you are pulling your own weight. Some tension with parties isn't always a bad thing, as long as it's kept to CHARACTER tension, and not player tension.
You can make a different character, that fits more in line of the party.
As an aside, while -murder- is probably an evil act, killing someone in their sleep is not, in and of itself, murder. (Let's face it, in a RPG where characters have divine mandates, etc, they all to often ARE the legitimate authorities for executing an evil foe, not as murder, but as a just execution.)