Differential Beamforming Random Access for Millimeter-Wave Systems
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Solution Overview
Problem
The random access procedure in millimeter-wave communication systems is inefficient due to the time-consuming process of searching for an optimal beam pair during initial connection establishment, leading to prolonged access time delays and suboptimal user experience.
Innovation Solution
The implementation of differential beamforming, which uses a sum beam and a differential beam to determine beam direction errors and adjust beamforming coefficients, allowing for faster detection of preamble sequences and reduced contention probability by optimizing the selection of optimal beam pairs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional beamforming is used for random access in millimeter-wave systems, then beam direction can be determined, but the time required to search for optimal beam pairs is excessively long
Solution Approach 1:
The patent segments the beam search process into two distinct phases: a coarse search phase using wide sum beams to identify candidate directions, and a fine search phase using narrow differential beams to precisely determine optimal beam pairs. This segmentation reduces the overall search time by avoiding exhaustive scanning with narrow beams while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary beam direction estimation using sum beams before conducting the fine beam pair search with differential beams. This preliminary action identifies candidate beam directions in advance, reducing the search space for the subsequent fine search and thereby reducing total random access time.
2Measurement precision
If exhaustive beam pair searching is performed during random access, then optimal beam pairs can be found, but access time delay increases significantly
Solution Approach 1:
The beam search is divided into coarse and fine stages. The coarse stage using sum beams provides preliminary direction estimation with lower precision but faster execution. The fine stage using differential beams refines the beam pair selection with higher precision. This segmented approach achieves optimal beam pair selection accuracy without the time penalty of exhaustive searching.
Solution Approach 2:
The sum beam provides preliminary beam direction estimation that narrows down the search space before the differential beam performs fine-tuned beam pair selection. This preliminary action ensures that the final beam pair selection is accurate while avoiding the need to exhaustively search all possible beam pairs.
3Reliability
If traditional random access procedure is used in millimeter-wave systems, then connection establishment can be achieved, but user experience deteriorates due to prolonged access delays
Solution Approach 1:
By segmenting the beam search into coarse and fine phases, the patent reduces the time required for connection establishment while maintaining reliability. The sum beam phase quickly identifies candidate directions, and the differential beam phase confirms optimal beam pairs, enabling faster connection establishment that improves user experience without sacrificing connection reliability.
Data Source
AI summary
The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure provides a differential beamforming based random access method, base station, and user equipment, wherein the differential beamforming based random access method comprises, by a base station: receiving a preamble sequence from a first terminal in a differential beamforming receiving mode; determining a base station beam direction angular deviation based on the preamble sequence; and adjusting a base station beam according to the base station beam direction angular deviation, and transmitting a random access response signal to the first terminal through the adjusted base station beam. In the present disclosure, by detecting a base station beam direction angular deviation in a differential beamforming receiving mode, a base station receiving beam can be adjusted to an optimal beam faster than a beam polling way of the prior art, thereby improving the performance of a random access procedure.