İşbirlikli Telsiz Haberleşmede Melez Otomatik Tekrar İsteği Yöntemleri

Abstract

In wireless communication systems, it is quite difficult to maintain an error-free communication because of fading and presence of noise. In order to overcome this problem, many different communication techniques are developed. Channel coding is one of the primer techniques among them. In channel coding, it is aimed to transmit the packets to the receiver after coding by some variety of algorithms. The receiver is supposed to detect the erroneously received packets by using these codes and request a retransmission (ARQ). It is aimed to correct the packet errors at the receiver side, if possible, since the performance of the system will affected adversely especially when packet errors are frequently encountered. To achieve this objective, hybrid automatic repeat request (HARQ) methods are developed with packets are supplied with error correcting codes in order to correct the errors to decrease the request for retransmissions and request a retransmission only if the errors are not correctable.