Patent ID: 8793563

Claim:
A method for de-masking a packet, the method being used in a wireless apparatus of a network system, the network system comprising a base station and the wireless apparatus, the method comprising the steps of: receiving, by the wireless apparatus, the packet from the base station, the packet comprising a data portion and a cyclic redundancy check portion; generating, by the wireless apparatus, a de-masked packet by de-masking the cyclic redundancy check portion and at least one selected bit of the data portion by a plurality of predetermined bits; determining, by the wireless apparatus, that the de-masked packet passes a cyclic redundancy check; and accepting, by the wireless apparatus, the packet; wherein the data portion has at least one selected position for placing the at least one selected bit, the at least one selected position corresponds to a plurality of possible bit streams, a first vector space is formed by a plurality of redundancies by applying a cyclic redundancy check polynomial to each of the possible bit streams, a second vector space is further formed by a plurality of redundancies by applying the CRC polynomial to each of all possible bit streams in the CRC portion, and the first vector space and the second vector space do not overlap.