SC-FDMA Transmit Diversity via Symbol Vector Segmentation
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Solution Overview
Problem
Wireless communication systems face challenges in achieving full transmit diversity while maintaining a single-carrier waveform for each transmit antenna, which is essential for efficient data transmission and battery life in power-limited devices.
Innovation Solution
The technique involves forming symbol vectors with modulation symbol sequences and their inverted, cyclically shifted, and conjugated versions, combined with cyclic prefixes and postfixes, to transmit data from two antennas in a single SC-FDMA symbol period, ensuring full transmit diversity and a single-carrier waveform for each antenna.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transmit diversity is implemented using multiple transmit antennas, then data transmission reliability is improved, but device complexity increases
Solution Approach 1:
The patent segments the data transmission by dividing it into two parts: a first part transmitted from a first antenna and a second part transmitted from a second antenna. This segmentation allows transmit diversity to be implemented without requiring complete redundancy across all antennas, thereby improving reliability while controlling device complexity. The receiver can recover the complete data by combining the received parts from different antennas.
2Reliability
If transmit diversity is implemented, then data transmission reliability is improved, but processing overhead increases
Solution Approach 1:
The patent applies partial action by transmitting only portions of the data from each antenna rather than complete redundant copies. The first antenna transmits a first part of the data while the second antenna transmits a second part. This partial transmission approach achieves diversity gain without the full processing overhead of traditional transmit diversity schemes that require complete signal replication and complex combining at the receiver.
3Use of energy by moving object
If single-carrier waveform is maintained for each transmit antenna, then power amplifier efficiency is improved, but transmit diversity performance is degraded
Solution Approach 1:
The patent applies local quality by maintaining the single-carrier waveform property locally at each individual transmit antenna while achieving global transmit diversity through the coordinated transmission of different data parts from multiple antennas. Each antenna independently maintains its single-carrier characteristic for power amplifier efficiency, while the system as a whole achieves diversity gain through the distributed transmission structure.
Data Source
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AI summary
Techniques for transmitting data with transmit diversity for single-carrier frequency division multiple access (SC-FDMA) are described. In one design, a transmitter (e.g., a UE) may form a first symbol vector including first and second modulation symbol sequences. The transmitter may also form a second symbol vector including third and fourth modulation symbol sequences, which may be generated based on the second and first modulation symbol sequences, respectively. Each symbol vector may further include a cyclic prefix and possibly a cyclic postfix for each modulation symbol sequence. The transmitter may generate a first SC-FDMA symbol based on the first symbol vector and a second SC-FDMA symbol based on the second symbol vector. The transmitter may transmit the first and second SC-FDMA symbols from two transmit antennas in a single SC-FDMA symbol period to achieve transmit diversity.