Does oc improve signal strength?
No, overclock has to do with the processor, just like in a computer. No offense, but you really shouldn't mess with your CPU too much if you don't know what you're doing. You might break something irreparably.
The Aphotic Chaotic
LG G2 VS980 (Verizon) [JB 4.3] PAC-man ROM
Nexus 7 [JB 4.2.2] XenonHD