Perfect Omnidirectional Pre-Coding Matrix for Large-Scale MIMO Systems
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Solution Overview
Problem
Existing methods for omnidirectional signal transmission in large-scale MIMO systems, such as single antenna transmission and space-time block coding, are inefficient and cannot guarantee perfect omnidirectional coverage, leading to power inefficiency and increased pilot overhead as the number of antennas increases.
Innovation Solution
A method involving the generation of synchronization signals and their pre-coding using a perfect omnidirectional pre-coding matrix W, which ensures equal power distribution in each spatial direction and across antennas, maximizing power efficiency and reducing pilot overhead through dimension reduction and orthogonal sequence sets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If single antenna transmission is used for omnidirectional signal broadcasting, then signal coverage is guaranteed, but power efficiency is reduced and cost increases due to requiring a larger power amplifier
Solution Approach 1:
The patent segments the omnidirectional transmission function across multiple antenna units instead of concentrating power in a single antenna. Each antenna unit transmits with equal, lower power, and through coherent combination achieves the desired omnidirectional coverage without requiring any single antenna to have excessive power amplification capability
Solution Approach 2:
The patent merges the transmission signals from multiple antenna units through coherent combination at the receiver side. By coordinating the phase and amplitude of signals from multiple low-power antenna units, the system achieves equivalent coverage to a single high-power antenna while maintaining superior power efficiency
2Reliability
If space-time block coding or cyclic delay diversity is applied for omnidirectional transmission, then signal diversity is improved, but pilot overhead increases linearly with the number of antennas
Solution Approach 1:
The patent applies a universal pre-coding structure that works across all antenna units with a fixed, small set of pilot signals. The pre-coding matrix design allows the same pilot sequence to be used regardless of the number of antenna units, making the pilot overhead independent of system scale while maintaining diversity benefits
Solution Approach 2:
The patent changes the fundamental parameter of pilot signal dimension from scaling with antenna number to being fixed. By redesigning the pilot structure to work with the pre-coded signal space rather than individual antenna signals, the system achieves diversity without linearly increasing pilot overhead
3Productivity
If traditional omnidirectional transmission methods are expanded to large-scale MIMO, then system capacity increases, but transmission performance deteriorates due to inability to guarantee equal power in each spatial direction
Solution Approach 1:
The patent transforms the transmission problem from individual antenna spatial distribution to a structured pre-coding matrix operation in signal space. By operating in the pre-coding domain and then transforming to the antenna domain, the system achieves precise control over spatial power distribution across all directions simultaneously, regardless of the number of antenna units
Solution Approach 2:
The patent uses a structured pre-coding matrix that creates coordinated copies of the transmitted signal across multiple antenna units with specific phase and amplitude relationships. This structured copying ensures that the combined radiation pattern achieves perfect omnidirectional characteristics with equal power distribution in all spatial directions
Data Source
AI summary
An EnodeB or a transmitting device intermittently generates synchronization signals, and then performs perfect omnidirectional pre-coding processing on the synchronization signals; the synchronization signals after perfect omnidirectional pre-coding processing pass through a transmission channel and are then received by a mobile terminal or a receiving device, and the mobile terminal or the receiving device uses the received synchronization signals and local replicas of the synchronization signals for receiving and synchronization processing. An EnodeB or a transmitting device generates vector signals via low-dimensional space-time coding, and then performs perfect omnidirectional pre-coding processing on the vector signals; the transmitted signals after perfect omnidirectional pre-coding processing pass through a transmission channel and are then received by a mobile terminal or a receiving device, and the mobile terminal or the receiving device uses the received signals for signal receiving processing.