Random Phase Multicast Signal Blocks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
UE reception of multicast data is disrupted due to destructive interference of multicast signals in existing multicast transmission systems, particularly at cell boundaries where signals from multiple base units can cancel out, leading to weak signal strength and reliability issues.
Innovation Solution
Applying a random phase to blocks within multicast transmissions by dividing downlink signals into phase blocks, each with a randomly selected phase, ensuring that signals from different base units are not aligned, thus minimizing destructive interference and achieving full diversity without increasing reference symbol overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multicast data is transmitted from multiple base units simultaneously, then coverage area and service capability are improved, but destructive interference occurs causing signal cancellation and reception disruption
Solution Approach 1:
The patent applies preliminary action by pre-randomizing the phase of each phase block before transmission. This preliminary phase randomization ensures that when multiple base units transmit multicast data simultaneously, their signals do not align in phase and cause destructive interference. The phase randomization is performed in advance on the downlink signal before it is sent to user equipment, thereby preventing the harmful alignment effect while maintaining the benefits of multi-base-unit transmission for extended coverage.
2Strength
If signals from multiple transmission points are combined, then signal strength is improved, but destructive interference causes signal cancellation at cell boundaries
Solution Approach 1:
The patent converts the harmful effect of phase alignment into a beneficial outcome. By intentionally randomizing the phase of each phase block before transmission, the system ensures that signals from multiple transmission points do not align constructively to cause destructive interference. Instead, the phase randomization transforms the potential harm of multi-point transmission into a benefit where signals combine more reliably, improving overall signal strength and reception quality, particularly at cell boundaries where interference is most problematic.
3Reliability
If phase randomization is applied to multicast transmission, then destructive interference is minimized, but system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the downlink signal into multiple phase blocks, each of which is independently phase-randomized. This segmentation approach allows the system to apply phase randomization in a manageable, modular fashion rather than attempting to randomize the entire signal at once. Each phase block can be processed independently with its own random phase applied, which reduces the computational complexity compared to processing the complete signal as a single unit, while still achieving the goal of minimizing destructive interference across the multicast transmission.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
For applying a random phase to blocks within a multicast transmission, methods, apparatus, and systems are disclosed. One apparatus 400 includes a processor 405 and a transceiver 425 that communicates with at least one remote unit 105. The processor 405 divides 705 a downlink transmission into a plurality of phase blocks, each phase block including a plurality of resource blocks. The processor 405 applies 710 a random phase to signals corresponding to each of the plurality of phase blocks, forming a randomly-phased transmission. Moreover, the transceiver 425 transmits 715 the randomly -phased transmission to the at least one remote unit 105 as multicast data.