The operation of the projection code is introduced, and the error rate
performance is determined, A new combinatorial generating function te
chnique is used to compute the weight distribution of a cylindrical pr
ojection code, which is then employed to obtain upper and lower bounds
of the bit error rate of the code, We then apply a state equation tec
hnique to compute the generating function of a convolutional projectio
n code. This new generating function technique is needed since the sta
ndard state-diagram technique cannot realistically be used to obtain t
he generating function of a typical convolutional projection code whic
h can have a constraint length of 56.