Wireless Communication Apparatus Adaptive Modulation
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Solution Overview
Problem
Adaptive modulation schemes in wireless communication struggle to maintain communication when line quality is significantly degraded, often resulting in reduced transmission speed even when line quality is good, due to the need for increased gain in control signals and increased processing for blind modulation methods.
Innovation Solution
A wireless communication apparatus and method that includes a symbol synthesis circuit, demodulation circuit, error correction circuit, detection circuits for error detection codes, and a received data selection circuit to determine and select the modulation scheme based on detection results, allowing for high-gain modulation even in degraded line quality without affecting transmission speed when quality is good.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a modulation scheme with a large transmission capacity is used, then transmission capacity is improved, but bit error incidence increases
Solution Approach 1:
The patent implements adaptive modulation that dynamically switches between different modulation schemes (BPSK, QPSK, 16QAM, 64QAM) based on real-time line quality assessment. This allows the system to optimize the balance between transmission capacity and bit error incidence by selecting the appropriate modulation scheme for current channel conditions.
Solution Approach 2:
The patent changes the modulation scheme parameter according to line quality conditions. When line quality is good, higher-order modulation schemes (64QAM) are used for maximum capacity. When line quality degrades, the system switches to lower-order schemes (BPSK, QPSK) to maintain reliability.
2Reliability
If a modulation scheme of low bit error incidence is used, then reliability is improved, but transmission capacity decreases
Solution Approach 1:
The system dynamically adjusts modulation scheme selection based on line quality feedback. Instead of using a fixed low-capacity modulation scheme for reliability, the system switches to higher-capacity schemes when line quality permits, thus avoiding unnecessary capacity loss while maintaining reliability when needed.
Solution Approach 2:
The modulation scheme parameter is changed according to line quality conditions. The system uses lower-order modulation (BPSK, QPSK) only when line quality is poor, and switches to higher-order modulation (16QAM, 64QAM) when line quality is good, optimizing the trade-off between reliability and capacity.
3Reliability
If direct spreading is used to obtain processing gain, then reliability is improved, but transmission speed decreases
Solution Approach 1:
Instead of always using direct spreading to obtain processing gain, the patent changes the modulation scheme parameter based on line quality. This allows the system to achieve reliable communication through adaptive modulation selection rather than relying solely on processing gain from spreading, thus avoiding the transmission speed penalty.
4Reliability
If data is repeatedly transmitted to increase gain, then reliability is improved, but transmission speed decreases
Solution Approach 1:
The patent avoids repeated transmission by changing the modulation scheme parameter according to line quality. The adaptive modulation allows the system to achieve reliable communication in a single transmission by selecting the appropriate modulation scheme for current conditions, eliminating the need for repeated transmissions and their associated speed penalties.
Data Source
AI summary
Provided is a wireless communication apparatus, comprising: a symbol synthesis circuit that synthesizes received symbols; a demodulation circuit that demodulates the received symbols each before and after the synthesis; an error correction circuit that corrects demodulated received data from the demodulation circuit; a detection circuit that detects a first error detection code from the error corrected received data; a second detection circuit that detects a second error detection code obtained by inverting a plurality of arbitrary bits from the error corrected received data; a received data selection circuit that selects the received data, wherein: the received data selection circuit determines a modulation scheme used upon transmission by using detection results of the first and second error detection codes and selects received data corresponding to the determined modulation scheme.