Low Code Rate Spatial Multiplexing for LTE-A PUCCH
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Solution Overview
Problem
Current multi-antenna transmission techniques for LTE-A PUCCH face limitations in robustness and efficiency, particularly in channel conditions, as they often require additional orthogonal resources, increased peak power, and reduced robustness to multipath, which restricts the number of users that can share the same resources.
Innovation Solution
The implementation of Low Code Rate Spatial Multiplexing (LCRSM) technique, which uses a lower channel code rate than single antenna transmission, allowing more robust transmission and increased coding gain, and is backward compatible with existing LTE codes, enabling efficient use of a single orthogonal resource across multiple antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional multi-antenna transmission techniques are used for LTE-A PUCCH, then transmission robustness is improved, but additional orthogonal resources are required and peak power increases
Solution Approach 1:
The patent combines transmit diversity and spatial multiplexing into a unified low code rate spatial multiplexing scheme. By merging these techniques, the system achieves transmission robustness through diversity while maintaining spectral efficiency, eliminating the need for additional orthogonal resources that would otherwise be required when using diversity techniques alone.
Solution Approach 2:
The patent changes the code rate parameter by using a lower code rate for multi-antenna transmission compared to single antenna transmission. This parameter change enables the system to achieve robust transmission with lower code rate while maintaining the ability to support multiple users on the same resources, thereby resolving the contradiction between robustness and resource consumption.
2Reliability
If traditional multi-antenna transmission techniques are used for LTE-A PUCCH, then transmission robustness is improved, but peak power requirements increase
Solution Approach 1:
By merging transmit diversity with spatial multiplexing, the patent achieves robust transmission without the peak power penalties that would otherwise be required. The combined scheme allows for more efficient power utilization across multiple antennas while maintaining diversity gains, thereby resolving the contradiction between robustness and peak power requirements.
3Reliability
If traditional multi-antenna transmission techniques are used for LTE-A PUCCH, then transmission robustness is improved, but robustness to multipath is reduced
Solution Approach 1:
The patent applies different spreading sequences to different antennas, creating local quality differences in the transmission characteristics. This allows the system to maintain robustness to multipath by ensuring that each antenna contributes differently to the overall transmission, thereby resolving the contradiction between general transmission robustness and specific multipath robustness.
4Reliability
If additional orthogonal resources are used for multi-antenna transmission, then transmission robustness is improved, but the number of users that can share resources is reduced
Solution Approach 1:
The patent merges transmit diversity with spatial multiplexing to achieve robust transmission without requiring additional orthogonal resources. This merging enables multiple users to share the same resources simultaneously while maintaining diversity gains, thereby resolving the contradiction between robustness and user capacity.
Solution Approach 2:
By changing the code rate parameter to use a lower code rate for multi-antenna transmission, the patent enables the system to support more users on the same resources. This parameter change allows for efficient resource utilization while maintaining transmission robustness, thereby resolving the contradiction between robustness and the number of supported users.
Data Source
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AI summary
A system is provided for transmitting a low code rate spatially multiplexed channel on multiple antennas. The system includes a transmitter and a processor. The processor is configured such that the processor encodes a block of information bits to form channel coded bits, wherein the ratio of the number of channel coded bits to the number of information bits is greater than one; and the processor maps the channel coded bits to modulation symbols, and each channel coded bit is mapped once to a modulation symbol. The transmitter is configured to transmit a first portion of the modulation symbols using a spreading sequence on a first antenna of the multiple antennas and to transmit a second portion of the modulation symbols using the spreading sequence on a second antenna of the multiple antennas.