Well I think I think the law should reverse engineer the original sentence, the truth is that rape in my country according to sub section 34 of the criminal code under rape, if the victim of the rape is below 18 years, then this may attract a life sentences because apart from rape they'll also be charged with peodophilosm as well.
However in case where the victim is above 18 the person involved may be getting up to 12 years without an option of fine.
I don't think there are laws to punish people who wrongly accused others of rape, at least not that I know of in my country and I'll be have definitely searched for,in the constitution of other countries in west Africa but I definitely cannot find, however maybe the united states definitely would.
However like I said earlier the best way will be the reverse engineer the judgement or rulings in court really.
I think a person who is capable of accusing another person wrongly of rape is capable of rape themselves and if I'm prosecuting them, I'll be prosecuting them on charges of false accusations, slander, defamation of character and criminal intent this alone will bag a sentences of 3 years then as the judge in charge of the ruling I'll also rule pervation of Justice which will land this false accusers of 12 years in jail or consult the accused victim to see if they'll collect compensation of wrong conviction, if not then the false accurser will get a reverse engineered sentencing and go to jail in a 14 sentence
Seeing as there are no specific laws addressing false accusations of rape. That will ultimately be determined by a competent court of law. most cases involving defamations (i.e, libel and slander) do not carry prison sentences for the accusers, rather they offer compensations for the victims.
I also feel this is wrong, as one stands at great risk just by being accused in a case such as rape. A good way to handle this will be to set up equivalent or semi equivalent prison time for deliberate false accusers that is usually handed to the accused along with the compensation packages the victim gets when found innocent of the accused crime