Presentation on theme: "Proposal of Different CRC Masks for Concatenated Subband Assignment A- MAP IEs (126.96.36.199.2.4) Document Number: IEEE C802.16m-10/0041 Date Submitted: 2010-3-5."— Presentation transcript:
Proposal of Different CRC Masks for Concatenated Subband Assignment A- MAP IEs (188.8.131.52.2.4) Document Number: IEEE C802.16m-10/0041 Date Submitted: 2010-3-5 Source: Yan-Xiu Zheng, Chang-Lan Tsai E-mail: email@example.com Yu-Chuan Fang, Chung-Lien Ho firstname.lastname@example.org ITRI Venue: IEEE 802.16 Session#66 at Orlando, USA. Base Contribution: Purpose: Propose to be discussed and adopted by TGm for the use in Project 802.16m/D4 Notice: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the Source(s) field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat
Motivation When the subband allocation is made using two concatenated IEs, there shall exist a bit in subband A-A- MAP for indicating the IE to be concatenated with the previous or next IE for subband allocation. The same CRC mask is used for the two concatenated subband A-A-MAP IEs. There would be hesitation in searching concatenated subband A-A-MAP IEs.
Example 1 IE 1 and IE 4 are single IEs with STID 1 and STID 4, respectively. The CRC masks are (0000|STID 1 ) and (0000|STID 4 ), respectively. The one bit indicator NumIEs is set to 0 representing a single IE. IE 2 and IE 3 are concatenated for subband allocation. They have the same STID and CRC mask which are STID 2 and (0000|STID 2 ), respectively. The one bit indicator NumIEs is set to 1 representing that the IE is concatenated with another IE with NumIEs equaling 1.
Example 1 In the case that the two subband A-A-MAP IE 2 and IE 3 are decoded correctly and CRC check is success, since the indicator NumIEs == 1 in subband IE 2, AMS check the next subband IE content to find the IE with NumIEs == 1 and combine these two IEs for subband allocation. In the case that the CRC check for IE 2 is failure, IE 2 is discarded. And if CRC check for IE 2 is success, since the indicator NumIEs == 1, AMS has to seek another subband IE with NumIEs == 1. This wastes logic processing time.
Distinct CRC Masks on Concatenated IEs We propose to use distinct CRC mask for the second IE of the two concatenated subband A-A-MAP IEs. –CRC mask = (0010|STID) Using the previous example for explanation. Now CRC mask of the second subband IE is (0010|STID 2 ).
CRC Check In the case that CRC check of subband IE 2 is success using CRC mask (0000|STID 2 ) and the indicator NumIEs == 1, the next subband IE is check by CRC mask (0010|STID 2 ). If the CRC check of subband IE 2 is success, then IE 2 and IE 3 are combined for subband allocation In the case that the CRC check for IE 2 is failure using CRC mask (0000|STID 2 ), IE 2 is discarded. AMS continues using CRC mask (0000|STID 2 ) to check IE 3. Of course the check would be failure.
Text Modification [Modify Table 819 on page 461] Masking Prefix Description 0b0CRC is masked by 1 bit masking prefix, 3 bit message type indicator, and 12 bit Masking Code The 3-bit type indicator shall be set/interpreted as follows. 000: 12 bit Masking Code refers to an STID (i.e. CRC mask = 0000| Masking Code) 010: 12 bit Masking Code refers to an STID used to mask the second IE if two assignment A-MAP IEs are concatenated for resource allocation (i.e. CRC mask = 0010| Masking Code) 001: 12 bit Masking Code used to mask Broadcast Assignment A-MAP IE, BR-ACK A-MAP IE, and Group Resource Allocation A-MAP IE, which is described in Table 820 (i.e. CRC mask = 0001| Masking Code). 0b1CRC is masked by 1 bit masking prefix, and 15 bit RAID (i.e. CRC mask = 1|RAID)