Parallel DS-CDMA UWB Initial Synchronization Module
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Solution Overview
Problem
The DS-CDMA UWB system faces challenges in efficiently acquiring initial symbol and frame synchronization, as well as compensating for synchronization errors caused by frequency offsets, due to its complex design and ultra-wide frequency band, which complicates the process of packet data communication.
Innovation Solution
A parallel processed DS-CDMA UWB system with a correlator and initial synchronizer that correlates input signals, performs symbol coherent and noncoherent combining, and stores synchronization position and mark values in a register to achieve simultaneous symbol and frame synchronization, while compensating for frequency offset errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate modules are used for compensating frequency offset and tuning packet synchronization and symbol synchronization, then the synchronization accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple separate synchronization modules (frequency offset compensation module, packet synchronization tuning module, and symbol synchronization tuning module) into a single integrated initial synchronization module. This module uses a unified search algorithm that processes correlation results to simultaneously determine packet synchronization position, symbol synchronization position, and frequency offset compensation parameters, thereby reducing device complexity while maintaining synchronization accuracy
Solution Approach 2:
The initial synchronization module is designed with multi-functionality to perform multiple synchronization tasks simultaneously. It can identify packet synchronization position, symbol synchronization position, and frequency offset in a single operation, making the system more efficient and less complex compared to using separate dedicated modules for each function
2Productivity
If a parallel structure is used for the correlator and searcher to process high-speed data, then the processing speed is improved, but the device complexity increases
Solution Approach 1:
The patent segments the synchronization acquisition process into distinct functional stages within the parallel structure: correlation computation stage, search detection stage, and synchronization determination stage. Each stage processes data independently at high speed, and the results are combined to achieve simultaneous packet and symbol synchronization, maintaining high processing speed while managing complexity through functional segmentation
3Loss of time
If the initial synchronization is acquired within a short preamble transmission period, then the time efficiency is improved, but the measurement precision deteriorates
Solution Approach 1:
The patent performs preliminary correlation computations during the preamble transmission period, accumulating correlation results as the preamble is received. The search algorithm uses these pre-computed correlation values to rapidly determine synchronization positions and frequency offset parameters, enabling accurate synchronization to be achieved within the constrained short time window of the preamble transmission
Data Source
AI summary
Provided are an initial synchronization acquiring device and method in a parallel processed DS-CDMA UWB system and a DS-CDMA UWB system's receiver using the same. The initial synchronization acquiring device is constructed to include a correlator for correlating input signals and outputting correlation result values and an initial synchronizer for tuning initial symbol synchronization and frame synchronization by using the correlation result values received from the correlator and then storing combining mark values and a synchronization position value in a register, thereby making it possible to greatly decrease a system's complexity, compared to the existing method of separately designing respective modules for acquiring packet synchronization and symbol synchronization in the existing CDMA system. Also, the initial synchronization acquiring device and method additionally compensates a synchronization error caused by a frequency offset generated between clocks used by a transmitter and a receiver and thereby can be efficiently used in the high-speed and parallel-processed DS-CDMA UWB system.