The Three Trivial Perfect Codes












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On Coding Theory, there's three trivial perfect codes.



They are:




  • Binary codes of odd length

  • Codes with contains only one codeword

  • Codes that are the whole $A^n_q$


So, the $A^n_q$ case, considering the definition that says "A perfect code is a code such $A_q^n$ is the disjoint union of balls of some fixed radius centered on the codewords" is trivial by taking the radius to be 0.



But the other two cases I can't see why. Any hints to demonstrate that?
(Could it be that codes with one codeword are analogue to the $A_q^n$ case? Taking the radius to be n or M=|C|)










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  • For the second case, yes, just take your radius to be suitably large, and you're done. For the first, this should help.
    – user3482749
    Dec 27 '18 at 13:59










  • Oh, I see it now! Thanks!
    – Rodrigo Geaquinto Gonçalves
    Dec 27 '18 at 15:01
















0














On Coding Theory, there's three trivial perfect codes.



They are:




  • Binary codes of odd length

  • Codes with contains only one codeword

  • Codes that are the whole $A^n_q$


So, the $A^n_q$ case, considering the definition that says "A perfect code is a code such $A_q^n$ is the disjoint union of balls of some fixed radius centered on the codewords" is trivial by taking the radius to be 0.



But the other two cases I can't see why. Any hints to demonstrate that?
(Could it be that codes with one codeword are analogue to the $A_q^n$ case? Taking the radius to be n or M=|C|)










share|cite|improve this question






















  • For the second case, yes, just take your radius to be suitably large, and you're done. For the first, this should help.
    – user3482749
    Dec 27 '18 at 13:59










  • Oh, I see it now! Thanks!
    – Rodrigo Geaquinto Gonçalves
    Dec 27 '18 at 15:01














0












0








0







On Coding Theory, there's three trivial perfect codes.



They are:




  • Binary codes of odd length

  • Codes with contains only one codeword

  • Codes that are the whole $A^n_q$


So, the $A^n_q$ case, considering the definition that says "A perfect code is a code such $A_q^n$ is the disjoint union of balls of some fixed radius centered on the codewords" is trivial by taking the radius to be 0.



But the other two cases I can't see why. Any hints to demonstrate that?
(Could it be that codes with one codeword are analogue to the $A_q^n$ case? Taking the radius to be n or M=|C|)










share|cite|improve this question













On Coding Theory, there's three trivial perfect codes.



They are:




  • Binary codes of odd length

  • Codes with contains only one codeword

  • Codes that are the whole $A^n_q$


So, the $A^n_q$ case, considering the definition that says "A perfect code is a code such $A_q^n$ is the disjoint union of balls of some fixed radius centered on the codewords" is trivial by taking the radius to be 0.



But the other two cases I can't see why. Any hints to demonstrate that?
(Could it be that codes with one codeword are analogue to the $A_q^n$ case? Taking the radius to be n or M=|C|)







coding-theory






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 27 '18 at 13:53









Rodrigo Geaquinto Gonçalves

62




62












  • For the second case, yes, just take your radius to be suitably large, and you're done. For the first, this should help.
    – user3482749
    Dec 27 '18 at 13:59










  • Oh, I see it now! Thanks!
    – Rodrigo Geaquinto Gonçalves
    Dec 27 '18 at 15:01


















  • For the second case, yes, just take your radius to be suitably large, and you're done. For the first, this should help.
    – user3482749
    Dec 27 '18 at 13:59










  • Oh, I see it now! Thanks!
    – Rodrigo Geaquinto Gonçalves
    Dec 27 '18 at 15:01
















For the second case, yes, just take your radius to be suitably large, and you're done. For the first, this should help.
– user3482749
Dec 27 '18 at 13:59




For the second case, yes, just take your radius to be suitably large, and you're done. For the first, this should help.
– user3482749
Dec 27 '18 at 13:59












Oh, I see it now! Thanks!
– Rodrigo Geaquinto Gonçalves
Dec 27 '18 at 15:01




Oh, I see it now! Thanks!
– Rodrigo Geaquinto Gonçalves
Dec 27 '18 at 15:01










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