Uplink Downlink Carrier Mapping Alignment for Interference Cancellation
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Solution Overview
Problem
The introduction of new communications technologies like wireless backhaul and dynamic TDD systems in LTE systems leads to uplink and downlink signals coexisting on the same time-frequency resource, causing interference due to different carrier mapping manners, which hampers interference cancellation in receivers.
Innovation Solution
A method and apparatus that ensure uplink and downlink signals use the same carrier mapping manner on a shared time-frequency resource, involving spectrum shifting and demodulation reference signal mapping adjustments to align carrier and RE mapping, enabling effective interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If new communications technologies (wireless backhaul, dynamic TDD) are introduced to improve resource usage, then resource efficiency is improved, but interference between uplink and downlink signals increases due to different carrier mapping manners
Solution Approach 1:
The patent changes the carrier mapping parameters by aligning the resource element (RE) mapping patterns of uplink and downlink signals. Specifically, it modifies the RE mapping configuration so that reference signals and data signals are mapped to the same time-frequency resource positions for both uplink and downlink, enabling the receiver to apply unified interference cancellation algorithms and thereby reducing signal interference while maintaining improved resource usage efficiency.
2Reliability
If different carrier mapping manners are used for uplink and downlink signals, then each signal can use its optimized mapping, but interference cancellation performance deteriorates
Solution Approach 1:
The patent applies homogeneity by making the resource element mapping patterns of uplink and downlink signals identical. Both uplink and downlink signals use the same RE mapping rule where reference signals and data signals are mapped to corresponding time-frequency positions, creating homogeneous mapping structures that enable the receiver to apply unified interference cancellation processing and thereby improving interference cancellation accuracy while maintaining signal transmission reliability.
Data Source
AI summary
Embodiments of the present invention disclose a transmission method, where includes: a receiver receives a communication signal, where the communication signal includes an uplink signal and a downlink signal that are transmitted on a same time-frequency resource, the uplink signal and the downlink signal use a same carrier mapping manner; and performs interference cancellation on the communication signal according to the first multiple access manner and the second multiple access manner. In the embodiments of the present invention, an uplink signal and a downlink signal that are transmitted on a same time-frequency resource use a same carrier mapping manner. In this way, after a new technology is introduced, a problem that carrier mapping manners of an uplink signal and a downlink signal that are on a same time-frequency resource are different can be overcome, which helps a receiver of a communication signal perform interference cancellation.