ACK CQI Pilot Structures Using Orthogonal Sequences
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Solution Overview
Problem
Existing wireless communication systems face challenges in reliably transmitting acknowledgement (ACK) and channel quality indicator (CQI) information due to interference and resource allocation inefficiencies, particularly in multiple-access systems like CDMA, TDMA, and OFDMA, where concurrent transmission of data and pilot signals on the same resources can lead to interference and reduced performance.
Innovation Solution
The proposed solution involves using frequency-domain and time-domain code division multiplexing (CDM) techniques to transmit data and pilot signals for ACK and CQI information, where UEs are assigned specific reference signal sequences and orthogonal sequences to generate multiple pilot and data sequences, allowing simultaneous transmission on the same subcarriers with minimal interference, and the Node B performs complementary processing to recover the control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple UEs transmit data and pilot signals simultaneously on the same resources in CDMA/TDMA/OFDMA systems, then resource utilization and productivity are improved, but interference increases and reliability deteriorates
Solution Approach 1:
The patent segments the transmission resources by dividing the available time-frequency resources into distinct regions for data and pilot signals. Different UEs are assigned different resource segments, allowing simultaneous transmission while reducing interference. This is achieved through resource block allocation and orthogonal resource assignment in the time-frequency domain.
Solution Approach 2:
The patent introduces additional dimensions for resource allocation beyond traditional time and frequency, utilizing code domain through orthogonal sequences and spreading codes. This multi-dimensional resource allocation (time-frequency-code) enables multiple UEs to transmit simultaneously on the same time-frequency resources with minimal interference, improving both productivity and reliability.
2Productivity
If data and pilot signals are transmitted on the same resources, then resource utilization is improved, but measurement precision of channel quality deteriorates due to interference
Solution Approach 1:
The patent extracts pilot signals from the data transmission resources by allocating dedicated pilot regions separate from data regions. This extraction allows pilot signals to be transmitted with higher power and better protection, ensuring accurate channel quality measurement even when data and pilot share the same overall resource pool. The separated pilot regions are specifically designed for channel estimation purposes.
Solution Approach 2:
The patent applies local quality by providing enhanced protection and dedicated resources for pilot signals in specific time-frequency regions. Different regions have different quality requirements - pilot regions are optimized for measurement accuracy with higher power allocation and protection, while data regions are optimized for throughput. This local differentiation ensures channel quality assessment accuracy is maintained.
3Device complexity
If conventional multiplexing is used for ACK and CQI transmission, then device complexity is reduced, but reliability of control information transmission deteriorates
Solution Approach 1:
The patent introduces dedicated physical channels (PUCCH formats) as intermediaries for ACK and CQI transmission, separating control information from data transmission. These specialized channels with dedicated resource allocation, modulation schemes, and error protection mechanisms provide reliable control information transmission without significantly increasing overall system complexity, as the complexity is standardized and handled by dedicated processing blocks.
Data Source
AI summary
Techniques for transmitting data and pilot for control information are described. In one aspect, a user equipment (UE) may spread a reference signal sequence with a first orthogonal sequence to obtain multiple pilot sequences. The UE may then send the multiple pilot sequences on multiple subcarriers in multiple symbol periods, one pilot sequence in each symbol period. The UE may modulate the reference signal sequence with control information (e.g., ACK information) to obtain a modulated sequence. The UE may spread the modulated sequence with a second orthogonal sequence to obtain multiple data sequences. The UE may then send the multiple data sequences on the multiple subcarriers in multiple symbol periods for data. In another aspect, the UE may send multiple pilot sequences on multiple subcarriers in multiple symbol periods separated by at least one symbol period, one pilot sequence in each symbol period.