短语词组短語cyclic -prefix cp 循環前綴non -cyclic-prefix 無循環前綴normal cyclic prefix 循環前綴CP Cyclic Prefix 循環前綴extended cyclic prefix 擴展循環前綴insuffcient cyclic prefix 循環前綴不足training cyclic prefix 循環訓練前綴cyclic prefix based 循環前綴 返回 cyclic prefix