Random Beamforming Wireless Communication System Interference Control
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Solution Overview
Problem
Current wireless communication systems face challenges in maximizing system capacity, especially in environments with low channel variation and high correlation between antennas, where techniques like multi-user diversity and random beamforming are less effective, and existing methods suffer from mutual interference and high implementation complexity.
Innovation Solution
A wireless communication method and apparatus that generates multiple beams with controllable interference using multiple antennas, allowing for simultaneous transmission of signals to multiple users, thereby achieving both multi-user diversity and multiplexing gains, even in environments with high channel correlation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple random beams are generated for simultaneous transmission to multiple users, then system capacity increases through multi-user diversity and multiplexing gains, but interference between different beams increases
Solution Approach 1:
The patent converts the harmful interference between random beams into a beneficial selection criterion. By deliberately generating multiple random beams that inherently cause interference, and then selecting the best beam based on instantaneous channel conditions, the system transforms interference from a problem to be avoided into a mechanism that enables multi-user diversity gain. The interference becomes part of the random variation that helps different users experience different channel qualities.
Solution Approach 2:
The patent changes the parameters of beam generation by using random weight vectors with randomly varying phases and amplitudes. Instead of using fixed or optimized beamforming weights, the system employs random parameters that change over time, creating multiple beams with different spatial characteristics. This parameter randomization allows the system to exploit channel variations and achieve multiplexing gains while managing interference through statistical properties.
2Productivity
If opportunistic scheduling is used to select users with highest instantaneous SNR, then system capacity increases in fading channels, but the technique becomes ineffective in environments with low channel variation such as fixed wireless access
Solution Approach 1:
The patent introduces dynamics into an otherwise static channel environment by generating time-varying random beams. Even in fixed wireless access scenarios where the physical channel is stable, the random beam weights create artificial channel variations that enable opportunistic scheduling to function. The system dynamically changes beam characteristics over time, creating the channel variation needed for user selection based on instantaneous SNR.
Solution Approach 2:
The patent performs preliminary beam generation with random weights before user selection. By pre-generating multiple random beams with different spatial characteristics, the system prepares multiple transmission options that exploit multi-user diversity. This preliminary action creates the conditions necessary for effective opportunistic scheduling, allowing users to be selected based on their instantaneous channel quality relative to the random beams.
3Quantity of substance
If multiple beams are transmitted simultaneously to achieve multiplexing gains, then more users can be served, but interference between beams degrades signal quality
Solution Approach 1:
The patent generates more random beams than strictly necessary, creating an excessive number of beam options. By generating multiple random beams beyond the minimum required for the number of users, the system ensures that at least some beams will have favorable interference characteristics for each user. This excessive action provides a larger pool of candidates, allowing the selection process to find beams that maintain signal quality while serving multiple users.
Data Source
AI summary
The object of the present invention is to provide a wireless communication method and apparatus, which obtains both Multi-User Diversity (MUD) and Multi-User Multiplexing (MUM) effects simultaneously using multiple beams having random weights. In the wireless communication method, a transmission stage having M antennas (M is an integer equal to or greater than 1) selects B reception stages (B is an integer equal to or greater than 1) among K reception stages (K is an integer equal to or greater than 1) each having N antennas (N is an integer equal to or greater than 1) and generates B beams to transmit B signals in a multiple-access transmission manner. In the wireless communication method, the weight vector wb=[w1,b, w2,b, . . . , wM,b] is determined to generate the b-th beam (b is an integer equal to or greater than 1 and equal to or less than B) corresponding to the b-th signal among B signals so as to determine the weight of output values respectively allocated to M antennas for the purpose of respectively generating B signals. The weight vector is determined so that respective elements thereof are determined to prevent interference between the different beams of B beams from exceeding a preset threshold. B signals are transmitted through B multiple channels obtained by generating B beams depending on the weights of elements.