Provisional Search Space for Control Channel Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multi-component carrier systems, user equipment face challenges in correctly detecting their control channels amidst multiplexed control channels, leading to potential failure in decoding data channels, and the random access procedure is inefficient, especially in achieving uplink sync due to propagation delays and resource allocation limitations.
Innovation Solution
The method involves transmitting a random access preamble on an activated secondary serving cell, monitoring physical downlink control channel candidates in a provisional search space, and adjusting the uplink time based on a time advance command received in the random access response, thereby reducing the overhead and battery consumption of user equipment and enhancing system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If user equipment monitors multiple control channel candidates in multiplexed control channels, then the probability of correctly detecting control information increases, but the complexity of blind decoding and processing increases significantly
Solution Approach 1:
The patent segments the control channel monitoring process by introducing a provisional search space that is separate from the common search space. This segmentation allows user equipment to first monitor a reduced set of candidates in the provisional search space to obtain timing advance commands, before proceeding to monitor control channels in the common search space. This division reduces the overall blind decoding complexity while maintaining detection reliability.
Solution Approach 2:
The patent implements preliminary action by requiring user equipment to first monitor control channel candidates in the provisional search space before monitoring the common search space. This preliminary monitoring step allows the base station to provide timing advance commands that synchronize uplink timing, which is a prerequisite for successfully receiving and decoding control information in the common search space. This staged approach reduces processing complexity by preparing the system in advance.
2Reliability
If user equipment performs random access procedure on secondary serving cells, then uplink synchronization can be achieved, but the overhead and battery consumption increase due to additional monitoring and processing
Solution Approach 1:
The patent extracts the timing advance command transmission function from the common search space and places it in a dedicated provisional search space. This extraction allows user equipment to obtain timing advance commands with reduced monitoring overhead. By separating this function, the patent reduces the number of control channel candidates user equipment must monitor, thereby reducing battery consumption while maintaining uplink synchronization accuracy.
Solution Approach 2:
The patent applies partial action by implementing a simplified monitoring procedure for the provisional search space compared to the common search space. User equipment monitors fewer candidates in the provisional search space specifically for timing advance commands, rather than performing full blind decoding across all possible control channel candidates. This partial monitoring approach reduces energy consumption while still achieving the necessary uplink synchronization.
3Productivity
If control channels for multiple user equipments are multiplexed in one transmission interval, then resource utilization efficiency increases, but the difficulty of detecting individual control channels increases
Solution Approach 1:
The patent introduces a provisional search space as an intermediary between the user equipment and the common search space. This intermediary structure provides a preliminary stage where timing advance commands are transmitted with known parameters, reducing the detection difficulty. The provisional search space acts as a mediator that prepares the system for subsequent control channel reception in the multiplexed common search space, making the overall detection process more manageable.
Data Source
AI summary
The present description relates to an apparatus and method for receiving a control channel in a multi-component carrier system. The method for performing random access disclosed in the present description comprises the steps of: transmitting a random access preamble to a base station from an activated sub-serving cell; monitoring physical downlink control channel candidates during a response window one the basis of a certain aggregation in a temporary search space in a control region of the activated sub-serving cell, wherein the control region consists of a group of control channel elements; and adjusting an uplink time of the activated sub-serving cell according to a time advance command indicated by a random access response when the random access response, including a random access identifier corresponding to the random access preamble, is received in the response window.