位元交錯編碼調變是一個適合連續衰退通道的通道碼。在不完美的通道狀態資訊下，需要傳送前導符元做通道估測。當通道變化速度越快，前導符元須傳送較頻繁，所導致的速率損失也越大。所以在這篇論文裡我們使用16QAM調變，並串接位元交錯編碼調變與使用查表的相差編碼，接收端用非同調檢測，避免傳送前導符元速率損失的問題。模擬結果顯示，串接遞迴解碼的位元交錯編碼調變與使用查表的相差編碼，其錯誤率會比使用前導符元做通道估測的同調位元交錯編碼調變還要更好。 Bit-interleaved coded modulation is a channel code that is suitable for continuous fading channel.To obtain channel state information,the transmitter periodically inserts pilot symbols to offer the receiver the ability to estimate channel amplitude and phase reference.When channel varies faster,the frequency of inserts pilot symbols should be higher,then it causes the rate loss.In this paper,we combine bit-interleaved coded modulation with differential encoding by a look-up table and use 16QAM modulation.At the receiver,we use noncoherent detector to avoid the rate loss.Simulation results show that combined bit-interleaved coded modulation and iterative decoding with differential encoding by a look-up table has better error performance than inserted pilot symbols with coherent detector.
