Adjacent-Channel Interference Cancellation for DSRC Signal Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems like DSRC, self-interference from simultaneous transmission and reception on adjacent channels significantly affects signal detection and medium access, making it challenging to maintain reliable communication.
Innovation Solution
A method and apparatus that estimate the channel gain between transmitter and receiver, synchronize symbol timing, and perform interference cancellation by overlapping cyclic prefixes of received and transmitted symbols to reduce self-interference, allowing concurrent communication on adjacent channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a device transmits and receives simultaneously on adjacent channels, then communication efficiency and productivity are improved, but self-interference from transmission leaks into reception channel causing signal detection failures and medium access problems
Solution Approach 1:
The patent converts the harmful self-interference signal into a useful component for interference cancellation. By capturing the transmitted signal and processing it through channel estimation, the system generates an expected interference signal that is then subtracted from the received signal, turning the harmful leakage into a known quantity that can be removed.
Solution Approach 2:
The patent performs preliminary channel estimation and interference signal generation before the actual reception processing. The transmitted signal is captured and processed in advance to create the expected interference signal, which is then used to cancel interference from the received signal, enabling cleaner signal detection.
2Reliability
If transmission power is increased to improve signal strength, then communication reliability is improved, but interference energy spilled over to adjacent channels increases
Solution Approach 1:
The patent converts the harmful interference energy generated by high-power transmission into a useful reference signal. The transmitted signal, even at high power, is captured and processed to generate the expected interference signal, which is then subtracted from the received signal, allowing high transmission power without proportional increase in harmful interference effects.
3Measurement precision
If channel estimation is performed to enable interference cancellation, then interference removal accuracy is improved, but processing complexity and computational requirements increase
Solution Approach 1:
The patent uses the device's own transmitted signal as the reference for channel estimation, eliminating the need for external pilot signals or complex training sequences. The transmitted signal is captured from the device itself and processed to estimate the channel response, simplifying the overall system complexity while maintaining accuracy.
Data Source
AI summary
Methods and apparatus for reducing and/or eliminating the effect of self-interference are described. Various described methods and apparatus are well suited for use in DSRC WAVE systems in which a wireless communications device may acquire and use two DSRC channels, e.g., use one channel for reception while using another channel for transmission at the same time. A wireless communications device which is receiving a signal of interest on a first channel supports concurrent transmission on second channel, e.g., an adjacent channel. Controlled transmission timing synchronization with respect to the received signal of interest facilitates interference estimation and removal. Interference due to spillover energy from the transmission on the adjacent channel is estimated and removed from a received signal to facilitate recovery of the signal of interest.