Method and apparatus for recovery of particular bits of a frame

• US 7,752,522 B2
• Filed: 11/21/2006
• Issued: 07/06/2010
• Est. Priority Date: 06/05/2000
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Jou, Yu-Cheun, Odenwalder, Joseph P., Saifuddin, Ahmed
• Primary Examiner(s): Torres; Joseph D
• Application Number:
  US11/562,399
• Publication Number:
  US 20070089040A1
• Time in Patent Office: 1,323 Days
• Field of Search: 714/755
• US Class Current: 714/755
• CPC Class Codes: H03M 13/01 Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/35 Unequal or adaptive error protection, e.g. by providing a different level of protection according to significance of source information or by adapting the coding according to the change of transmission channel characteristics
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 2001/0098 Unequal error protection

Abstract

A method and an apparatus for recovery of particular bits in a frame are disclosed. An origination station forms a frame structure with groups of information bits of different importance. All the information bits are then protected by an outer quality metric. Additionally, the groups of more important information bits are further protected by an inner quality metric; each group having a corresponding quality metric. The frame is then transmitted to a destination station. The destination station decodes the received frame and decides, first in accordance with the outer quality metric, whether the frame has been correctly received, or whether the frame is erased. If the frame has been declared erased, the destination station attempts to recover the groups of more important information bits in accordance with the corresponding inner quality metrics.

Claims

1. A method comprising:

receiving a wireless frame comprising a plurality of groups corresponding to different classes, an outer-quality metric bit and an inner quality metric bit, the outer quality metric bit being used to verify whether the wireless frame has been received correctly and the inner quality metric bit being used to verify whether a corresponding group of information bits of a particular class contained in the wireless frame has been received correctly;

recovering information contained in the wireless frame including the corresponding group of information bits if it is determined that the wireless frame has been correctly received as indicated by the outer quality metric bit; and

if it is determined that the wireless frame has not been received correctly as indicated by the outer quality metric bit but the corresponding group of information bits has been correctly received as indicated by the inner quality metric bit, recovering the corresponding group of information bits from the wireless frame which has not been received correctly.

2. The method of claim 1 further comprising:

determining whether the wireless frame has been received correctly by checking the outer quality metric bit; and

if the wireless frame has not been received correctly as indicated by the outer quality metric bit, determining whether the corresponding group of information bits has been correctly received by checking the inner quality metric bit.

3. The method of claim 1 wherein the inner quality metric bit comprises a cyclic redundancy check (CRC) bit.

4. The method of claim 1 wherein the inner quality metric bit comprises a parity bit.

5. An apparatus comprising:

a decoder configured to;

receive and decode a wireless frame comprising a plurality of groups corresponding to different classes, an outer quality metric bit and an inner quality metric bit, the outer quality metric bit being used to verify whether the wireless frame has been received correctly, and

recover information contained in the wireless frame including a corresponding group of information bits if it is determined that the wireless frame has been received correctly as indicated by the outer quality metric bit; and

an inner quality metric processor coupled with the decoder for receiving an inner quality metric bit, the inner quality metric bit being used to verify whether the corresponding group of information bits of a particular class contained in the wireless frame has been received correctly,

wherein, if it is determined that the wireless frame has not been received correctly by the decoder as indicated by the outer quality metric bit but the corresponding group of information bits has been correctly received by the decoder as indicated by the inner quality metric bit, the corresponding group of information bits is recovered, using the decoder, from the wireless frame which has not been received correctly.

6. The apparatus of claim 5 wherein the decoder is further configured to determine whether the wireless frame has been received correctly by checking the outer quality metric bit, and

if the wireless frame has not been correctly received as indicated by the outer quality metric bit, the decoder determines whether the corresponding group of information bits has been correctly received by checking the inner quality metric bit.

7. An apparatus comprising:

means for receiving a wireless frame comprising a plurality of groups corresponding to different classes, an outer quality metric bit and an inner quality metric bit, the outer quality metric bit being used to verify whether the wireless frame has been received correctly and the inner quality metric bit being used to verify whether a corresponding group of information bits of a particular class contained in the wireless frame has been received correctly;

means for recovering information contained in the wireless frame including the corresponding group of information bits if it is determined that the wireless frame has been correctly received as indicated by the outer quality metric bit; and

means for recovering, if it is determined that the wireless frame has not been received correctly as indicated by the outer quality metric bit but the corresponding group of information bits has been correctly received as indicated by the inner quality metric bit, the corresponding group of information bits from the wireless frame which has not been received correctly.

8. A tangible computer-readable media comprising a computer program including a set of instructions for executing a process for a wireless communication device, the process comprising:

receiving a wireless frame comprising a plurality of groups corresponding to different classes, an outer quality metric bit and an inner quality metric bit, the outer quality metric bit being used to verify whether the wireless frame has been received correctly and the inner quality metric bit being used to verify whether a corresponding group of information bits of a particular class contained in the wireless frame has been received correctly;

recovering information contained in the wireless frame including the corresponding group of information bits if it is determined that the wireless frame has been correctly received as indicated by the outer quality metric bit; and

if it is determined that the wireless frame has not been received correctly as indicated by the outer quality metric bit but the corresponding group of information bits has been correctly received as indicated by the inner quality metric bit, recovering the corresponding group of information bits from the wireless frame which has not been received correctly.

9. The process of claim 8 further comprising:

determining whether the wireless frame has been received correctly by checking the outer quality metric bit; and

if the wireless frame has not been received correctly as indicated by the outer quality metric bit, determining whether the corresponding group of information bits has been correctly received by checking the inner quality metric bit.

10. The process of claim 8 wherein the inner quality metric bit comprises a cyclic redundancy check (CRC) bit.

11. The process of claim 8 wherein the inner quality metric bit comprises a parity bit.