Error detection code generating method and error detection code generator
In a mobile communication system, an error detection code or a quality frame indicator (e.g., CRC) is generated using selectively frame information, and at least one of a WCA identifier of another terminal, and a corresponding terminal identifier. And the terminal identifier can be implicitly transmitted to the receiver.
1. An apparatus for transmitting a packet through a physical layer channel in a mobile communication system, the apparatus comprising:
an error detection code addition unit for operations of a physical layer, wherein the error detection code addition unit is configured to:
receive, at a physical layer of the apparatus, an input bit sequence;
generate, at the physical layer of the apparatus, a first sequence by attaching a first error detection code to the input bit sequence, wherein the first error detection code is calculated based on the input bit sequence; and
attach, at the physical layer of the apparatus, a second error detection code to a second sequence generated from the first sequence in order to generate the packet, wherein the second error detection code is calculated based on the second sequence including the first error detection code,
wherein the apparatus is configured to transmit the packet through the physical layer channel which is a channel configured at the physical layer lower than a medium access control (MAC) layer.
2. The apparatus according to claim 1 , wherein the physical layer channel is used to transmit control information for a data unit transmission.
3. The apparatus according to claim 1 , wherein the first error detection code and the second error detection code are generated using different polynomials to each other.
4. The apparatus according to claim 2 , wherein the first error detection code is masked with a terminal identifier identifying a terminal.
5. The apparatus according to claim 4 , wherein the first sequence comprises variable size information corresponding to an encoder packet size field, an automatic request for repetition (ARQ) channel identifier field, a subpacket identifier field, a walsh code allocation field and a sequence number field.
6. The apparatus according to claim 1 , wherein the physical layer channel carries the control information multiplexed with data unit.
7. The apparatus according to claim 1 , wherein the control information comprises quality indicator, and wherein the quality indicator is multiplexed with data unit.