Staggered SACCH Frame Positioning in Half-Rate MUROS
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Solution Overview
Problem
Current downlink multiframe transmission solutions are insufficient for SACCH frames when MUROS multiplexing is performed in a half-rate channel, failing to meet the requirements for four subscribers, which affects voice quality.
Innovation Solution
The method involves staggering SACCH frames with one or more TCH frames during transmission in a half-rate channel, ensuring normal SACCH signaling and reducing voice quality impact by using different transmit powers for SACCH and TCH frames when they share the same timeslot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If MUROS multiplexing is performed in a half-rate channel to increase voice capacity, then more subscribers can share the same resource, but the number of SACCH frames becomes insufficient for all subscribers
Solution Approach 1:
The patent introduces a new dimension of frame structure by creating a 52-frame multiframe that extends beyond the traditional 26-frame structure. This allows SACCH frames to be distributed across multiple periods, ensuring that each subscriber receives adequate SACCH frames even when multiple subscribers share the same timeslot through MUROS multiplexing.
Solution Approach 2:
The patent pre-allocates specific frame positions within the 52-frame multiframe structure to ensure SACCH frame availability. By predeterminedly designing the frame structure with SACCH frames at specific intervals, the system ensures that control signaling requirements are met before the actual multiplexing operation begins.
2Productivity
If SACCH frames are multiplexed with TCH frames in the same timeslot to increase capacity, then resource utilization improves, but voice quality deteriorates due to interference
Solution Approach 1:
The patent segments the transmission resources by separating SACCH and TCH transmissions into different timeslots or different periods within the 52-frame multiframe structure. This segmentation prevents simultaneous transmission of SACCH and TCH in the same timeslot, thereby eliminating mutual interference while still achieving high resource utilization through the extended frame structure.
Solution Approach 2:
The patent implements periodic transmission patterns where SACCH frames are transmitted at specific intervals within the 52-frame multiframe, rather than continuously. This periodic action allows TCH transmission to occur in between SACCH transmissions, reducing interference while maintaining necessary control signaling frequency.
Data Source
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AI summary
A method and a device for transmitting the downlink multiframe are provided herein. The method includes: setting positions of the Slow Associated Control Channel ,SACCH, frames and Traffic Channel, TCH, frames of multiple subscribers in a multiframe, wherein the SACCH frame of each subscriber and one or more TCH frames of other subscribers multiplex a same timeslot of the multiframe in a half-rate channel; and transmitting the multiframe in a preset timeslot. By adjusting the positions of the SACCH frames and TCH frames of the multiplexing subscribers, the SACCH frame of a subscriber and the TCH frames of other subscribers multiplex in a same timeslot for transmission; that is, the SACCH frames of each subscriber are staggered during transmission. This ensures normal transmission of the SACCH signaling of all subscribers and reduces the effect on the voice quality.