Wireless Receiver Joint Detection for Co-Channel Interference
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Solution Overview
Problem
In wireless communication networks, especially those using GSM standards, multiple cell phones can interfere with each other, leading to degraded receive signal quality and dropped calls due to co-channel interference, which existing technologies struggle to effectively mitigate.
Innovation Solution
The implementation of a joint detection Viterbi (JDV) algorithm that demodulates both the desired signal and interference signal jointly, using training sequences and channel estimations to improve signal quality, along with adaptive selection between JDV and standard Viterbi demodulators based on signal characteristics like RSSI and propagation channel length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard demodulation techniques are used, then device complexity is reduced, but signal quality deteriorates due to interference from multiple cell phones
Solution Approach 1:
The received signal is segmented into multiple components: desired signal, interference signal, and noise. The JDV algorithm processes these segments separately by evaluating possible transmitted sequences for each component, allowing sophisticated interference cancellation without overwhelming computational complexity
Solution Approach 2:
Channel estimations serve as an intermediary between the raw received signal and the final demodulated data. The JDV algorithm first generates channel estimations by evaluating possible transmitted sequences, then uses these estimations to improve subsequent demodulation of data fields, effectively mediating the interference cancellation process
2Measurement precision
If joint detection Viterbi algorithm is applied to all data fields, then demodulation accuracy improves, but processing time increases
Solution Approach 1:
The JDV algorithm is applied preliminarily to the training sequence to generate channel estimations before processing the data fields. This preliminary action on the known training sequence provides accurate channel information that accelerates and improves subsequent demodulation of the unknown data fields, reducing overall processing time
Solution Approach 2:
The patent applies JDV algorithm selectively rather than uniformly - using it extensively on the training sequence where it provides maximum benefit for channel estimation, and then using these estimations to guide less computationally intensive processing of the data fields, achieving high accuracy without excessive processing time for the entire signal
3Reliability
If iterative application of JDV algorithm is used, then interference reduction improves, but computational complexity increases
Solution Approach 1:
The JDV algorithm is applied periodically in iterations: first to the training sequence to generate initial channel estimations, then to the data fields using these estimations, and potentially in subsequent refinement iterations. This periodic application structure achieves progressive interference reduction while managing computational complexity through structured repetition
Data Source
AI summary
A wireless receiver uses a joint detection Viterbi (JDV) algorithm to demodulate a signal that has a desired signal component and an interference signal component. The desired signal component includes a training sequence and at least one data field. The training sequence and a corresponding portion of the interference signal component is demodulated using the JDV algorithm to evaluate possible transmitted training sequences and interference signal sequences, and channel estimations for the desired signal component and the interference signal component are generated. The at least one data field is demodulated according to the JDV algorithm using the channel estimations as initial channel estimates for the JDV algorithm.