BICM Decoding With Interference Estimation for Full-Band Transmission
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Solution Overview
Problem
Current wireless communication protocols, such as GSM, reduce data transmission rates by decomposing frequency bands into multiple channels to avoid interference, limiting bandwidth and spectral efficiency due to the need for frequency reuse to counter co-channel interference.
Innovation Solution
Mobile stations compute soft information by estimating channel and modulation information from both intended and interfering sources, allowing them to accurately decode signals without requiring different frequency channels for neighboring base stations, thus enabling full-band data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency bands are decomposed into multiple channels to avoid interference, then communication reliability is improved, but data transmission rate deteriorates
Solution Approach 1:
The patent converts the harmful interference from neighboring base stations into useful information by estimating the interference channel and signal characteristics. The mobile station uses the known pilot signals and modulation schemes of interfering sources to compute expected interference, then subtracts this from the received signal to recover the intended signal, thereby maintaining reliability while using the full bandwidth without frequency decomposition
Solution Approach 2:
The patent changes the approach from frequency domain separation to signal domain processing. Instead of dividing frequency bands, the system processes signals in the time domain by estimating interference parameters (channel gain, modulation scheme) and subtracting the interference component, enabling full-band transmission while maintaining communication reliability
2Object-affected harmful factors
If frequency reuse is implemented to counter co-channel interference, then interference is reduced, but spectral efficiency deteriorates
Solution Approach 1:
The patent transforms the harmful co-channel interference into a measurable and compensatable effect. By estimating the interference channel gain and expected signal from neighboring base stations, the system converts the harmful interference into a known quantity that can be subtracted from the received signal, enabling frequency reuse factor of 1 while maintaining communication quality
Solution Approach 2:
The patent introduces an intermediary processing step between signal reception and decoding. The mobile station estimates the interference component as an intermediary element, then subtracts this estimated interference from the received signal before decoding, thereby eliminating the need for frequency reuse while maintaining performance
Data Source
AI summary
Systems and methods are provided for computing soft information for digital information based on a received signal, where the received signal suffers from noise and interference. A receiver that decodes the received signal may estimate channel information, such as the channel gain, associated with the interfering source. The receiver may also obtain modulation information through a backbone network or by decoding control information transmitted by the interfering source. Using the modulation information and the channel information, the receiver may estimate the effect that interference has on the received signal, and may compute soft information (e.g., a log-likelihood ratio) for the digital information.