The 

 -receiver Gaussian broadcast channel is a communication system in which a single codeword is transmitted over 

 distinct Gaussian channels and is received by 

 receivers. The receivers have no contact with each other and the channels have different signal-to-noise ratios. The purpose of this correspondence is to define the concept of group code for the 

 -receiver Gaussian broadcast channel and study permutation codes as a special case. Such a code is generated by an initial vector 

 , a group 

 of orthogonal 

 -by- 

 matrices, and a sequence of subgroups of 

 .