Method and apparatus for reducing uplink and downlink transmission errors by supporting adaptive modulation and coding and hybrid automatic repeat request functions
View Patent ↗A method and apparatus for supporting Adaptive Modulation and Coding (AM&C) and Hybrid Automatic Repeat Request (H-ARQ) functions in a cellular system including at least one wireless transmit/receive unit (WTRU) and a Node B. A signal is received at the WTRU indicating a need for AM&C and H-ARQ control signaling. An AM&C and H-ARQ control signaling transport channel (TrCH) is dynamically allocated by informing a transport format selection process of the need for AM&C and H-ARQ control signaling. The transport format is selected for required transmission time intervals (TTIs) which assign transport format combinations (TFCs) to establish the AM&C and H-ARQ control signaling transport channel.
1. A method for supporting adaptive modulation and coding (AM&C) and hybrid automatic repeat request (H-ARQ) functions, the method comprising:
receiving at a wireless transmit/receive unit (WTRU) a signal indicating a need for AM&C and H-ARQ control signaling;
dynamically allocating at least one AM&C and H-ARQ signaling transport channel by informing a transport format selection process of the need for AM&C and H-ARQ control signaling;
selecting a transport format set for required transmission time intervals (TTIs) of the transport channel which assign transport format combinations (TFCs) to establish the AM&C and H-ARQ signaling transport channel; and
aligning control channel TTIs with AM&C and H-ARQ transmissions on the AM&C and H-ARQ signaling transport channel such that each control channel TTI begins and ends at the same time as a corresponding AM&C and H-ARQ transmission.
2. The method of claim 1 further comprising changing dynamic attributes of the transport channel on a TTI basis by generating a transport format combination indicator (TFCI).
3. The method of claim 2 wherein the dynamic attributes of the transport channel include a payload size.
4. The method of claim 1 further comprising changing semi-static attributes of the transport channel using radio resource control (RRC) procedures.
5. The method of claim 4 wherein the semi-static attributes of the transport channel include a coding rate.
6. The method of claim 4 wherein the semi-static attributes of the transport channel include a TTI size.
7. The method of claim 4 wherein the semi-static attributes of the transport channel include a cyclic redundancy check (CRC).
8. A wireless communication apparatus comprising:
a receiver for receiving at a wireless transmit/receive unit (WTRU) a signal indicating a need for adaptive modulation and coding (AM&C) and hybrid automatic repeat request (H-ARQ) control signaling;
an allocator for dynamically allocating at least one AM&C and H-ARQ signaling transport channel by informing a transport format selection process of the need for AM&C and H-ARQ control signaling;
a selector for selecting a transport format set for required transmission time intervals (TTIs) of the transport channel which assign transport format combinations (TFCs) to establish the AM&C and H-ARQ signaling transport channel; and
an aligner for aligning control channel TTIs with AM&C and H-ARQ transmissions on the AM&C and H-ARQ signaling transport channel such that each control channel TTI begins and ends at the same time as a corresponding AM&C and H-ARQ transmission.
9. The apparatus of claim 8 wherein the allocator changes dynamic attributes of the transport channel on a TTI basis by generating a transport format combination indicator (TFCI).
10. The apparatus of claim 9 wherein the dynamic attributes of the transport channel include a payload size.
11. The apparatus of claim 8 wherein the allocator changes semi-static attributes of the transport channel using radio resource control (RRC) procedures.
12. The apparatus of claim 11 wherein the semi-static attributes of the transport channel include a coding rate.
13. The apparatus of claim 11 wherein the semi-static attributes of the transport channel include a TTI size.
14. The apparatus of claim 11 wherein the semi-static attributes of the transport channel include a cyclic redundancy check (CRC).