Parallel Demodulator Architecture for High Symbol Rate Timing Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current satellite communication systems face challenges in efficiently demodulating high symbol rate data streams due to limitations in clock speed requirements, which lead to increased design complexity and cost, particularly in maintaining accurate symbol timing recovery at high data rates.
Innovation Solution
A dynamic and flexible parallel architecture for symbol timing recovery that processes data streams at or below the modem's clock rate, preserving temporal dependencies between samples and reducing the need for high-frequency processing, allowing for efficient and robust broadband services in shared bandwidth networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional serial demodulation architecture is used to process high symbol rate data streams, then accurate symbol timing recovery can be achieved, but the processing clock frequency must be at least twice the symbol rate, leading to increased design complexity and manufacturing cost
Solution Approach 1:
The patent divides the high symbol rate data stream processing into multiple parallel channels, each operating at a lower clock frequency. By segmenting the processing tasks across parallel paths with different timing offsets, the system achieves accurate symbol timing recovery without requiring a single high-frequency clock, thus resolving the contradiction between timing accuracy and device complexity
Solution Approach 2:
The patent transitions from a single-dimensional serial processing approach to a multi-dimensional parallel processing architecture. By adding the dimension of parallel channels with staggered timing, the system can recover symbol timing accurately while operating at lower individual clock frequencies, effectively resolving the frequency requirement contradiction
2Device complexity
If parallel architecture is used to reduce processing clock frequency, then design complexity and cost are reduced, but maintaining accurate symbol timing recovery at high symbol rates becomes challenging
Solution Approach 1:
The patent incorporates feedback mechanisms where timing error detection results from multiple parallel channels are combined and used to adjust the timing offsets of subsequent processing stages. This feedback loop ensures that accurate symbol timing recovery is maintained despite the lower individual clock frequencies in each parallel channel
Solution Approach 2:
The patent merges the timing information from multiple parallel channels through a combination logic that integrates results from channels with different timing offsets. By combining these distributed measurements, the system achieves accurate symbol timing recovery that would be difficult to obtain in a single channel operating at lower frequency
3Productivity
If high processing clock frequency is used to handle high symbol rate data streams, then throughput is maintained, but timing constraints on physical design become tighter and manufacturing cost increases
Solution Approach 1:
The patent segments the high-throughput processing requirement into multiple parallel channels operating at relaxed timing constraints. Each channel processes a portion of the data stream at a manageable clock frequency, collectively achieving the required overall throughput while avoiding the manufacturing complexity associated with high-frequency design
4Measurement precision
If sampling rate is increased to at least twice the symbol rate for accurate demodulation, then symbol timing recovery is improved, but all front-end signal processing must be performed at this high rate, increasing system complexity
Solution Approach 1:
The patent implements dynamic timing offsets in the parallel channels, where each channel operates at a lower fixed clock rate but with adjustable phase relationships. This dynamic configuration allows the system to achieve the effective sampling rate requirement for accurate symbol timing while keeping individual processing stages at lower, less complex clock rates
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
A dynamic and flexible architecture and methods for demodulation of high data-rate streams with high symbol-rates, such as in satellite communications systems or computer network communications systems, is provided. A data stream of a data transmission is received, the data stream corresponding to a plurality of data symbols. A plurality of data samples corresponding to each of the data symbols is generated. Further, one or more representative data samples, corresponding each of the data symbols, are generated based at least in part on timing control signals and the generated data samples for the respective data symbol. The generated data samples corresponding to each of the data symbols other than the representative data samples are dropped. The timing control signals are then adjusted based at least in part on the generated representative data samples.