Method for decoding a received control channel message with a priori information
View Patent ↗A wireless communication device employs a method for receiving a message stream on a control channel. According to one embodiment, the wireless communication device receives a message on the control channel. The wireless communication devices attempts to decode the message and, if the message is successfully decoded, adds bits of the successfully decoded message to a message attributes list. Some time thereafter, the wireless communication device attempts to decode a subsequent message received on the control channel and, if an error is detected during decoding of the subsequent message, replaces bits in the subsequent message with bits from the message attributes list to produce a modified message. The wireless device then attempts to decode the modified message.
1. A method for a wireless communication device to receive a message stream on a wireless control channel, the method comprising:
receiving at least one message on the control channel;
attempting to decode the at least one message;
adding bits of the at least one message to a message attributes list if the at least one message is successfully decoded;
receiving a subsequent message on the control channel;
attempting to decode the subsequent message;
replacing bits in the subsequent message with bits from the message attributes list to produce a modified message if an error is detected during decoding of the subsequent message; and
attempting to decode the modified message.
2. The method according to claim 1 , wherein receiving a message on the control channel comprises receiving a message on a slow associated control channel.
3. The method according to claim 1 , wherein the message attributes list comprises a message prototype list, wherein the bits of the at least one message form at least one prototype message of the message prototype list, and wherein replacing bits in the subsequent message with bits from the message attributes list comprises replacing bits in the subsequent message with at least one prototype message stored in the message prototype list to produce the modified message.
4. The method according to claim 3 , wherein the at least one prototype message comprises at least one upper layer prototype message derived from bits in a communication protocol layer above a physical layer of the at least one message, and wherein replacing bits in the subsequent message with bits from the message attributes list comprises:
replacing bits in the subsequent message with at least one upper layer prototype message to produce the modified message.
5. The method according to claim 4 , wherein the message prototype list further includes at least one header prototype message derived from bits at the physical layer of the at least one message, and wherein replacing bits in the subsequent message with bits from the message attributes list Thither comprises:
replacing bits in the subsequent message with at least one header prototype message.
6. The method according to claim 4 , further comprising:
updating trellis state metrics of a forward error correction decoder to permit state transitions consistent with the at least one upper layer prototype message; and
selecting a decode sequence according to the trellis state metrics, but only permitting considered paths through a trellis in accordance with the at least one upper layer prototype message.
7. The method according to claim 4 , wherein replacing bits in the subsequent message with at least one upper layer prototype message comprises replacing bits of a upper communication protocol layer of the subsequent message with at least one layer 3 prototype message derived from bits of a layer 3 communication protocol layer of the at least one message.
8. The method according to claim 4 , wherein the message prototype list further includes at least one header prototype message derived from bits at the physical layer of the at least one message, the method further comprising:
detecting whether an error in decoding of the modified message occurred after bits of the upper communication protocol layer of the subsequent message were replaced with at least one upper layer prototype message from the message prototype list; and
if an error occurred, replacing a header field of the modified message with a header prototype message item the message prototype list.
9. The method according to claim 4 , wherein replacing bits in the subsequent message with at least one upper layer prototype message comprises replacing bits in the subsequent message with at least one prototype message derived from bits in at least one of a layer 2 communication protocol layer and a layer 3 communication protocol layer of the at least one message.
10. The method of claim 3 , wherein the at least one prototype message comprises at least one layer 2 prototype message derived from bits in a layer 2 communication protocol layer of the at least one message, and wherein replacing bits in the subsequent message with at least one prototype message stored in the message prototype list comprises:
replacing bits in the subsequent message with at least one layer 2 prototype message to produce the modified message.
11. The method of claim 10 , wherein replacing bits in the subsequent message with at least one layer 2 prototype message comprises replacing bits in the subsequent message with at least one prototype message derived from bits in a data link layer or a medium access control layer of the at least one message.
12. The method of claim 10 , wherein replacing bits in the subsequent message with at least one layer 2 prototype message comprises replacing a layer 2 message field of the subsequent message with a layer 2 prototype message from the message prototype list to produce the modified message.
13. The method according to claim 1 , wherein the message attributes list is a message prototype list and wherein adding bits of the at least one message to the message attributes list comprises:
updating a layer 2 prototype message set in the message prototype list with bits from a layer 2 communication protocol layer of the at least one message if the at least one message is successfully decoded.
14. The method according to claim 1 , wherein the message attributes list is a message prototype list ad wherein adding bits of the at least one message to the message attributes list comprises:
updating a layer 1 header prototype message set in the message prototype list with bits from at least one header of a layer 1 communication protocol layer of the at least one message if the at least one message is successfully decoded, wherein the layer 1 communication protocol layer of the at least one message corresponds to a physical layer of the at least one message.
15. The method according to claim 1 , wherein attempting to decode the at least one message comprises attempting to convolutionally decode the at least one message.