Uplink Precoding Codebook Design for Power Efficiency
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Solution Overview
Problem
Current multiple antenna systems face challenges in designing a codebook suitable for uplink transmission with an increased number of antennas, particularly in managing peak-to-average power ratio (PAPR) and power efficiency, especially when obstacles like hand grip situations occur, and when applying downlink codebooks to uplink scenarios with limited power amplifiers.
Innovation Solution
A 4Tx rank-3 codebook is designed for uplink transmission, incorporating precoding matrices with specific power normalization factors and configurations to optimize power allocation and reduce PAPR, allowing for effective data transmission with selective antenna usage and power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a downlink codebook is applied to uplink transmission with increased antennas, then spatial multiplexing capability is improved, but PAPR increases and power efficiency deteriorates
Solution Approach 1:
The patent modifies the codebook structure by introducing power normalization factors and adjusting precoding matrix configurations specifically for uplink transmission. This changes the parameters of the codebook to optimize power allocation across antennas, thereby maintaining spatial multiplexing capability while reducing PAPR and improving power efficiency in uplink scenarios
Solution Approach 2:
The patent enables dynamic selection of codebooks and precoding matrices based on uplink channel conditions and power constraints. By making the codebook selection adaptive rather than static, the system can optimize the trade-off between spatial multiplexing gain and power efficiency according to real-time transmission requirements
2Power
If output power is increased to transmit signal in low geometry, then signal transmission is improved, but PAPR increases due to limited power amplifier output
Solution Approach 1:
The patent introduces power normalization factors that scale the precoding matrices to control the peak power levels. By adjusting these normalization parameters, the system can transmit signals effectively in low geometry conditions while preventing excessive PAPR generation that would exceed power amplifier capabilities
3Productivity
If the number of antennas is increased to obtain higher data transfer rate, then data transfer rate is improved, but the number of codebook sets increases and system complexity increases
Solution Approach 1:
The patent segments the codebook into multiple codebook sets that can be selectively applied based on the number of active antennas and transmission rank. This segmentation allows the system to support higher data transfer rates with multiple antennas while managing complexity by only activating the necessary subset of codebook sets for each transmission scenario
Solution Approach 2:
The patent implements partial codebook activation where not all codebook sets are used simultaneously. Instead, specific codebook sets are activated based on the transmission configuration, thereby achieving high data transfer rates with increased antennas while avoiding the full complexity burden of maintaining and processing all possible codebook sets
Data Source
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AI summary
A data transmission method in a multiple antenna system is provided. The method includes: defining a codebook including at least one precoding matrix composed of a plurality of rows and columns, wherein the codebook is at least one of a first type in which all elements of the precoding matrix are non-zero elements, a second type in which any one column of the precoding matrix includes non-zero element and the remaining columns include at least one zero element, and a third type in which all columns of the precoding matrix include at least one zero element; precoding an input symbol by using the defined codebook; and transmitting the precoded symbol.