Uplink Channel Sounding Reference Signal Multiplexing in SC-FDMA
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Solution Overview
Problem
In SC-FDMA-based wireless communication systems, existing technologies face challenges in efficiently multiplexing Channel Sounding Reference Signals (CS RS) with other uplink control channels while maintaining constant resource allocation and ensuring the same ACK/NACK channel transmission capacity in slots with and without CS RS transmission.
Innovation Solution
The method involves transmitting CS RS symbols through selected Long Blocks in a time slot and applying an orthogonal sequence to control channels in remaining blocks, allowing CS RS to be fixedly allocated across terminals and maintaining equal ACK/NACK channel capacity in all slots by using the same orthogonal sequence length for both slots with and without CS RS transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Channel Sounding Reference Signals are multiplexed with other uplink control channels in SC-FDMA systems, then resource utilization improves, but interference between channels occurs and resource allocation becomes non-constant
Solution Approach 1:
The time slot is segmented into Long Blocks, with specific LBs allocated to CS RS transmission and others to control channels. This segmentation allows CS RS to be transmitted in designated blocks without interfering with control channels in other blocks, while still achieving efficient resource utilization across the entire slot.
Solution Approach 2:
Different regions of the time-frequency resource are assigned different functions: specific Long Blocks are dedicated to CS RS transmission while other LBs are dedicated to control channels. This local differentiation ensures that CS RS maintains constant resource allocation in its designated blocks without causing interference to control channels.
2Productivity
If Channel Sounding Reference Signals are transmitted in selected Long Blocks, then resource allocation efficiency improves, but ACK/NACK channel capacity varies between slots with and without CS RS transmission
Solution Approach 1:
The system dynamically adjusts the application of orthogonal sequences based on whether CS RS is transmitted in a slot. When CS RS is transmitted, orthogonal sequences are applied to control channels in remaining LBs; when CS RS is not transmitted, orthogonal sequences are applied to all LBs. This dynamic adaptation ensures consistent ACK/NACK channel capacity across all slots.
Solution Approach 2:
The orthogonal sequence application parameter is changed based on the presence of CS RS transmission. The system modifies whether orthogonal sequences are applied to control channels depending on the slot type, ensuring that the effective capacity for ACK/NACK transmission remains consistent regardless of CS RS presence.
3Reliability
If orthogonal sequences are applied to control channels in slots with CS RS transmission, then channel separation improves, but system complexity increases due to different processing for different slot types
Solution Approach 1:
The system determines in advance whether CS RS will be transmitted in a slot and pre-configures the orthogonal sequence application accordingly. This preliminary determination simplifies the processing by avoiding the need for complex real-time decisions about whether to apply orthogonal sequences, reducing overall system complexity while maintaining reliable channel separation.
Data Source
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AI summary
Provided is a method for transmitting an uplink Channel Sounding (CS) Reference Signal (RS) channel in a wireless communication system. The method includes transmitting symbols of the CS RS channel through an entire system band in a previously selected at least one of Long Blocks (LBs) constituting one time slot of a subframe; and transmitting symbols of control channels through a predetermined band in LBs remaining after symbols of the CS RS channel are applied in the time slot, by applying an orthogonal sequence determined according to the number of LBs to which symbols of the CS RS channel are applied.