MIMO Transmitter SS-STBC Precoding Adaptation
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Solution Overview
Problem
Classical SS-STBC schemes in MIMO or MISO telecommunication systems face issues such as high complexity, sensitivity to fast channel modifications, and interference, especially in millimeter-Wave systems like 5G, due to phase variations and interference from multiple terminals using the same scheme.
Innovation Solution
A method is introduced that adapts the SS-STBC pre-coding by adjusting the value of p to optimize symbol pairing and precoding distance, reducing decoding errors and interference, and is compatible with various reference signal insertion patterns and channel conditions, using a pre-coder that applies a specific transformation to the symbols before DFT and IDFT processing for transmission on multiple antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If classical SS-STBC pre-coding is applied to achieve full diversity and low PAPR in MIMO/MISO systems, then transmission reliability is improved, but the system becomes sensitive to fast channel modifications and phase variations in millimeter-Wave systems
Solution Approach 1:
The patent applies dynamics by making the cyclic prefix length adaptive rather than fixed. The CP length is dynamically adjusted based on channel conditions, allowing the system to adapt to fast channel modifications in millimeter-Wave environments while maintaining the benefits of SS-STBC pre-coding for diversity and PAPR performance
Solution Approach 2:
The patent changes the parameter of cyclic prefix length to resolve the contradiction. By modifying this parameter adaptively according to channel conditions, the system maintains reliability through SS-STBC while becoming versatile enough to handle fast fading and phase variations characteristic of millimeter-Wave communications
2Productivity
If multiple terminals use the same SS-STBC scheme simultaneously, then system capacity is improved, but interference between terminals increases due to phase variations
Solution Approach 1:
The patent applies local quality by allowing each terminal to independently select its own cyclic prefix length based on its specific channel conditions and interference environment. This localized adaptation reduces inter-terminal interference while maintaining overall system capacity, as each terminal optimizes its transmission parameters for its local context rather than all terminals using identical fixed parameters
3Object-generated harmful factors
If the block of symbols is divided into two parts with optional cyclic prefixes and postfixes to limit interference, then interference between parts is reduced, but the implementation complexity increases
Solution Approach 1:
The patent applies partial action by making the cyclic prefix and postfix optional rather than mandatory. The system can selectively apply these elements based on interference conditions, achieving interference reduction when needed while avoiding the complexity overhead when interference is not an issue, thus balancing performance improvement with implementation simplicity
Data Source
AI summary
The invention relates to transmitting symbols in a MIMO wireless communication system, said method comprising: determining a p value; applying to a first block of M data symbols X=(X0, . . . XM-1) a pre-coder to obtain a second block of M symbols Y=(Y0, . . . YM-1) with Formula (I); applying a M size DFT then a N size IDFT to the first block of M symbols to obtain a first SC-FDMA symbol, said first SC-FDMA symbol being of a given duration; applying a M size DFT then a N size IDFT to the second block of M symbols to obtain a second SC-FDMA symbol, said second SC-FDMA symbol being of the given duration; transmitting during a time interval of the given duration, simultaneously the first and second SC-FDMA symbols, into the radio signal.