Communication system with iterative detector and decoder and method of operation thereof

A method of operation of a communication system comprising:

• receiving an input signal having an input primary codeword and an input parallel codeword;
• calculating a primary codeword signal by removing a parallel soft information average of the input parallel codeword from the input signal;
• filtering residual parallel interference of the input parallel codeword from the primary codeword signal with a primary whitening filter to generate a primary codeword estimation of the input primary codeword;
• calculating a primary detected soft information for the primary codeword estimation;
• and
• calculating a primary channel soft information of the input primary codeword based on the primary detected soft information for communicating with a device.

A communication system comprising:

• a signal receiver module for receiving an input signal having an input primary codeword and an input parallel codeword;
• an primary interference cancellation module, coupled to the signal receiver module, for calculating a primary codeword signal by removing a parallel soft information average of the input parallel codeword from the input signal;
• a primary signal whitening module, coupled to the primary interference cancellation module, for filtering a residual parallel interference of the input parallel codeword from the primary codeword signal with a primary whitening filter to generate a primary codeword estimation of the input primary codeword;
• and
• a primary modified detection module, coupled to the primary signal whitening module, for calculating a primary detected soft information for the primary codeword estimation for communicating with a device.