Random Access Preamble Timing Offset for Wide Cell Coverage
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Solution Overview
Problem
Current random access techniques in wireless communication systems face challenges in accommodating a wider cell radius while using a shorter cyclic prefix, leading to decreased energy efficiency and signal-to-noise performance due to longer CP lengths.
Innovation Solution
A method and apparatus for random access in wireless communication systems that determine a timing offset value based on signal characteristic values and preset threshold information, allowing for earlier transmission of the random access preamble, thereby accommodating a wider cell radius with a shorter cyclic prefix length, reducing energy consumption, and improving SNR performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a longer cyclic prefix is used to accommodate a wider cell radius, then the cell coverage area is improved, but the energy consumption increases and signal-to-noise performance deteriorates
Solution Approach 1:
The terminal performs preliminary actions by measuring downlink signal characteristics (RSRP, RSSI, RSRQ, or SINR) and calculating timing offset values before transmitting the random access preamble. This preliminary measurement and calculation enable the terminal to compensate for propagation delay and advance its transmission timing, allowing the use of shorter cyclic prefixes while maintaining wide cell coverage capability.
Solution Approach 2:
The invention changes the timing parameter of random access preamble transmission by introducing a timing offset value derived from downlink signal measurements. This parameter change allows the terminal to transmit the preamble earlier than the conventional timing, effectively extending the usable cell radius without requiring a longer cyclic prefix, thus resolving the contradiction between cell coverage and energy consumption.
2Area of stationary object
If a longer cyclic prefix is used to accommodate a wider cell radius, then the cell coverage area is improved, but the signal-to-noise ratio performance deteriorates
Solution Approach 1:
The terminal performs preliminary measurements of downlink signal characteristics and calculates the appropriate timing offset before preamble transmission. This preliminary action enables accurate timing advancement compensation, ensuring that the preamble arrives at the base station at the correct time even with a shorter cyclic prefix, thereby maintaining signal-to-noise ratio performance while supporting wider cell coverage.
Solution Approach 2:
By changing the transmission timing parameter through the calculated timing offset, the invention enables the random access preamble to be transmitted earlier in the uplink frame structure. This parameter change allows shorter cyclic prefixes to be used effectively, maintaining orthogonality and reducing inter-symbol interference, thus preserving signal-to-noise ratio performance while extending cell coverage area.
3Area of stationary object
If a longer cyclic prefix is used, then the cell radius is increased, but the resource utilization efficiency decreases
Solution Approach 1:
The invention changes the timing parameter of random access preamble transmission by introducing a timing offset value calculated from downlink signal measurements. This parameter change allows the terminal to transmit the preamble earlier, enabling the use of shorter cyclic prefixes that consume fewer time resources, thereby improving resource utilization efficiency while maintaining or extending the achievable cell radius.
Data Source
AI summary
A random access method performed by a communication node may comprise: receiving RACH configuration information; measuring a distance between a base station and a terminal or a signal characteristic value corresponding to the distance between the base station and the terminal; determining a timing offset value to be applied to random access preamble transmission using the signal characteristic value, preset threshold value, and preset timing offset value; and transmitting a random access preamble generated on the basis of the RACH configuration information to the base station, wherein the threshold value and the timing offset value are included in the RACH configuration information.