Uplink Power Control In A Wireless Device

What is this patent about?

’201 is related to the field of multicarrier communication systems, specifically addressing the efficient management of uplink control channels (PUCCH) in scenarios with carrier aggregation (CA) and dual connectivity (DC). In modern wireless networks, user equipment (UE) often communicates with multiple cells simultaneously to increase data throughput. This requires transmitting control information, such as HARQ-ACK and channel state information (CSI), to the base station. The physical uplink control channel (PUCCH) is used for this purpose.

The underlying idea behind ’201 is to improve the handling of PUCCH transmissions by grouping cells into primary and secondary PUCCH groups. The key inventive insight is to allow a UE to determine the appropriate transmit power for either the primary or secondary PUCCH based on the cell from which it receives downlink control information (DCI). This determination is made without relying on specific DCI formats (3 or 3A), which are typically used for power control but may not be efficient or flexible enough for advanced CA and DC scenarios. The invention aims to optimize PUCCH resource utilization and reduce control channel overhead.

The claims of ’201 focus on a base station transmitting configuration parameters that define primary and secondary PUCCH groups. The base station then transmits downlink control information (DCI) for a cell, which includes a PUCCH transmit power control (TPC) command and scheduling information. The base station then receives uplink signals on either the primary or secondary PUCCH. The selection of which PUCCH to expect the uplink signals on is determined by whether the cell sending the DCI is the primary cell or the PUCCH secondary cell. The DCI format specifically excludes formats 3 and 3A .

In practice, the base station configures the UE with information about the PUCCH groups and their associated cells. When the base station schedules a transmission for a particular cell, it includes a TPC command in the DCI. The UE then uses this TPC command to calculate the transmit power for the appropriate PUCCH (primary or secondary) based on the cell from which the DCI was received. This allows for dynamic power control of PUCCH transmissions without the need for dedicated power control DCI formats.

This approach differs from prior solutions by providing a more flexible and efficient way to manage PUCCH power control in advanced wireless networks. By implicitly linking the TPC command to the cell transmitting the DCI, the invention avoids the overhead associated with explicit signaling of the target PUCCH. This is particularly beneficial in scenarios with a large number of aggregated carriers, where the control channel overhead can become a significant bottleneck. The invention simplifies the power control process and improves overall network performance.