Active Antenna Phase Offset Control for HSDPA Throughput
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Solution Overview
Problem
Existing transmission systems in mobile communication networks, particularly those using MIMO technology, face challenges in balancing power between antennas, which can negatively impact legacy HSDPA devices and reduce throughput in multiuser scenarios, especially when concurrent HSDPA and MIMO traffic share the same carrier.
Innovation Solution
The system dynamically adjusts phase offsets between sub-modules of active antennas to optimize transmit polarization, using a method that selects candidate phase offset vectors based on user-reported channel quality information to maximize throughput, particularly for HSDPA users, and employs Virtual Antenna Mapping to balance power between sub-modules, allowing for finer control of polarizations and improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If MIMO technology is used to improve system capacity and throughput, then network performance is improved, but power balance between antennas becomes difficult to maintain and legacy HSDPA devices experience performance degradation
Solution Approach 1:
The patent implements dynamic phase offset adjustment where the phase offset between antenna sub-modules is not fixed but adapted in real-time based on channel conditions and user equipment type. The system dynamically selects between different phase offset configurations (0 degrees for MIMO users, variable offsets for HSDPA users) to optimize performance for each user type while maintaining power balance across antennas.
Solution Approach 2:
The patent changes the phase offset parameter dynamically based on user equipment type and channel conditions. By adjusting the phase offset between sub-modules from a fixed value to a variable parameter that can be set to 0 degrees or other values depending on the active user type (MIMO vs HSDPA), the system resolves the contradiction between achieving high throughput and maintaining power balance with legacy device compatibility.
2Productivity
If phase offsets are adjusted to optimize transmit polarization for HSDPA users, then throughput is improved, but device complexity increases
Solution Approach 1:
The patent applies different phase offset configurations to different user equipment types rather than using a uniform configuration for all users. MIMO users receive signals with 0 degree phase offset between sub-modules, while HSDPA users receive signals with optimized phase offsets. This localized optimization approach improves HSDPA throughput without unnecessarily complicating the system for MIMO users.
Solution Approach 2:
The system uses channel quality information (CQI) feedback from user equipment to determine the appropriate phase offset configuration. The base station receives CQI measurements from users and uses this feedback to select the optimal phase offset setting, creating a closed-loop control system that adapts to actual channel conditions rather than relying on complex open-loop calculations.
3Reliability
If Virtual Antenna Mapping is used to balance power between sub-modules, then power distribution is improved, but control complexity increases
Solution Approach 1:
The patent segments the antenna system into distinct sub-modules with independent phase offset control. By dividing the transmit array into separable sub-module groups that can be independently configured, the system can apply Virtual Antenna Mapping to specific sub-module pairs without affecting the entire antenna system, thereby simplifying the control complexity while maintaining power balance.
Data Source
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AI summary
A transmission system and method for use in a mobile communication network comprising an active antenna arrangement of multiple antennas. The active antenna arrangement comprising several pairs of radiofrequency sub-modules each radiofrequency sub-module including a first phase shifter module , a TRX module and a radiating antenna element and where an dynamic phase offset is applied to one of the sub-modules of each pair, and where the phase offset vector is selected according to the signal quality received by users of the mobile communication network using an algorithm which minimizes the duration of the selection process.