Antenna Selection Module for OFDMA Transmit Diversity
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Solution Overview
Problem
In LTE-based OFDMA systems, the use of a single antenna for transmitting RACH bursts and user packet data leads to deep fading effects, particularly at higher mobile station speeds, resulting in reduced system performance and increased deep fading periods, which complicates signal demodulation and increases manufacturing costs due to the complexity and size of the transmitter apparatus.
Innovation Solution
A packet data transmission method utilizing multiple antennas in a mobile station, where a RACH burst is transmitted through a selected antenna and user packet data is sent when permission is granted, with the ability to switch to a different antenna if permission is denied, employing a symbol-subcarrier mapper, IFFT unit, and switching block to manage antenna selection and data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple antennas are used with transmit vector decision module and transmit antenna decision module, then data transmission reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the functions of transmit vector decision module and transmit antenna decision module into a single integrated antenna selection module. This merging eliminates redundant components and simplifies the overall transmitter structure while maintaining the capability to select optimal antennas for data transmission, thereby reducing device complexity without sacrificing transmission reliability.
Solution Approach 2:
The antenna selection module is designed to perform multiple functions: it selects transmit antennas based on channel conditions, determines transmit vectors, and adapts to different transmission scenarios (RACH bursts and data packets). This multi-functional design replaces multiple specialized modules with a single versatile component, reducing overall system complexity while maintaining reliability.
2Device complexity
If single antenna is used for transmitting RACH burst and user packet data, then device complexity is reduced, but deep fading effect increases particularly at higher mobile speeds
Solution Approach 1:
The patent implements dynamic antenna selection where the system adapts its transmit antenna configuration based on current channel conditions and mobile station speed. The antenna selection module continuously monitors fading conditions and switches between single-antenna and multi-antenna modes, or selects different antennas from the array, thereby dynamically optimizing transmission reliability without requiring a permanently complex multi-antenna transmitter structure.
3Adaptability or versatility
If transmit vector decision module and transmit antenna decision module are included, then antenna selection capability is improved, but the size of mobile station increases
Solution Approach 1:
The patent merges the transmit vector decision module and transmit antenna decision module into a single integrated antenna selection module, thereby reducing the overall volume occupied by these decision-making components in the mobile station while preserving their combined antenna selection and vector determination capabilities.
Data Source
AI summary
The present invention relates to a packet data transmission method in an OFDMA system and an apparatus thereof. The present invention provides a user packet data transmission method including generating a RACH burst for channel information estimation, selecting a first antenna among a plurality of antennas, transmitting the RACH burst through the first antenna to a base station, receiving a data transmission acceptance signal from the base station, in response to the RACH burst, transmitting user packet data through the first antenna when receiving a signal indicating that the data transmission is allowed, and selecting a second antenna that is difference from the first antenna and transmitting a RACH burst through the second antenna when receiving a signal indicating that the data transmission is not allowed, and a transmitting apparatus of a mobile station having the plurality of antennas. According to the present invention, the RACH burst and user packet data are transmitted by using a mobile station having a plurality of antennas in an LTE-applied OFDMA system, and therefore data transmission can be performed with a wide bandwidth and high data rate and a deep fading period that may occur during the data transmission can be reduced, thereby preventing call dropping and improving data transmission performance.