CDMA中283频点的中心频率是（）

A.825MHz-835MHz 870MHz-880MHz
B.815MHz-825MHz 860MHz-870MHz
C.815MHz-825MHz 870MHz-880MHz
D.825MHz-835MHz 860MHz-870MHz

A.TURBO编码
B.香农编码
C.卷积编码
D.SBC子带编码

A.originationmessage→BSACK→TCHpreamble→Channelassignmentmessage→BSACK→MSACK→ServiceConnectmessage→Serviceconnectcompletion→assignmentcomplete
B.originationmessage→BSACK→ServiceConnectmessage→TCHpreamble→BSACK→MSACK→Channelassignmentmessage→Serviceconnectcompletion→assignmentcomplete
C.originationmessage→BSACK→Channelassignmentmessage→TCHpreamble→BSACK→MSACK→ServiceConnectmessage→Serviceconnectcompletion→assignmentcomplete
D.OriginationMessage→CMServiceRequest→TchPreamble→Establish→AssignmentComplete→Allocation；