In this paper, a bidirectional system based on linear channel estimation and data detection using turbo detection algorithm is proposed. By combining channel estimation with an iterative chip-by-chip detection process (inner loop) in an iterative way (outer loop), communications performance can be further increased. The authors present results on blind reception in case of Interleave Division Multiple Access (IDMA) system when the channel coefficients are unknown. They develop a low-complexity iterative joint channel/code estimation method. The philosophy of the turbo processing is the iterative exchange of related information which yields a substantial improvement of the overall system performance. They analyze the achievable performance of the iterative system proposed. Simulation results demonstrate the efficiency of the proposed algorithms.