Apparatus and method for enabling low latency transmissions in the uplink of a communication system
Methods and apparatus are provided for a User Equipment (UE) to transmit signals in response to the reception of a Downlink Control Information (DCI) format transmitted from a base station of a communication system. The DCI format may provide only the frequency resources for the transmission of signals by the UE, while other parameters associated with the transmission of signals by the UE may be either predetermined or known to the UE through other signaling from the base station. The frequency resources used for the transmission of signals by the UE may be a sub-set of the frequency resources indicated by the DCI format and the determination of this sub-set by the UE may be either deterministic or pseudo-random.
1. In a communication system in which User Equipments (UEs) receive Downlink Control Information (DCI) formats transmitted through respective Physical Downlink Control Channels (PDCCHs) from a base station over a transmission time interval, a method for a UE to transmit signals in a Physical Uplink Shared Channel (PUSCH) over a communication system operating bandwidth in response to reception of a DCI format, the method comprising the steps of:
determining first frequency resources for transmission of the signals in the PUSCH from second frequency resources indicated by a first DCI format;
determining values of all other parameters for the transmission of the signals in the PUSCH by other signaling exclusive of the first DCI format; and
transmitting the signals in the PUSCH using the first frequency resources,
wherein the size of the first DCI format is same that of a second DCI format for Scheduling PCH (Paging Channel), RACH (Random Access Channel) Response or SIB (Secondary Information Block) Transmissions, and
wherein the all other parameters comprise the DCI Format Indication Flag, Modulation-Coding Scheme (MCS), New Data Indicator (NDI), Transmission Power Control (TPC), Cyclic Shift Indicator (CSI), Frequency Hopping (FH), CQI Request, Resource Allocation Type and Zero Padding.
2. The method of claim 1 , wherein the first frequency resources are the same as the second frequency resources.
3. The method of claim 1 , wherein the other signaling for determining the values of all other parameters comprise having predetermined values or having values informed to the UE by the base station either through broadcast signaling or through UE-specific signaling using higher layers.
4. The method of claim 1 , wherein PDCCH resources used for the transmission of the first DCI format are common to all UEs.
5. The method of claim 1 , wherein a range of the first frequency resources is smaller than the communication system operating bandwidth.
6. The method of claim 1 , wherein the second frequency resources are indicated by the first DCI format using a bit-map.
7. The method if claim 1 , wherein the first DCI format transmission occurs only in a subset of a set of transmission time intervals.
8. A User Equipment (UE) apparatus for transmitting signals in a Physical Uplink Shared Channel (PUSCH) over a communication system operating bandwidth of a communication system in response to reception of a Downlink Control Information (DCI) format transmitted through a Physical Downlink Control Channel (PDCCH) from a base station over a transmission time interval, the apparatus comprising:
a receiver for receiving a first DCI format and other signaling from the base station;
a controller for determining first frequency resources from second frequency resources indicated by the first DCI format and for determining values of all other parameters for the transmission of the signals in the PUSCH indicated by the other signaling from the base station; and
a transmitter for transmitting the signals in the PUSCH using the first frequency resources and using the all other parameters with the corresponding values,
wherein the size of the first DCI format is same that of a second DCI format for Scheduling PCH (Paging Channel), RACH (Random Access Channel) Response or SIB (Secondary Information Block) Transmissions,
wherein the all other parameters comprise the DCI Format Indication Flag, Modulation-Coding Scheme (MCS), New Data Indicator (NDI), Transmission Power Control (TPC), Cyclic Shift Indicator (CSI), Frequency Hopping (FH), CQI Request, Resource Allocation Type and Zero Padding.
9. The apparatus of claim 8 , wherein the first frequency resources are the same as the second frequency resources.
10. The apparatus of claim 8 , wherein the other signaling is either broadcast signaling or UE-specific signaling using higher layers from the base station, and wherein additional parameters exist for which values are specified by system operation.
11. The apparatus of claim 8 , wherein a range of the first frequency resources is smaller than the communication system operating bandwidth.
12. The apparatus of claim 8 , wherein the first frequency resources are indicated by the first DCI format using a bit-map.