Beam Switching Symbol Extension and Windowing
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Solution Overview
Problem
Wireless communication systems face challenges with residual radiation and adjacent-channel interference during beam switching due to undetermined RF front-end states and residual signaling, leading to out-of-band emissions and increased adjacent channel leakage ratio (ACLR).
Innovation Solution
The implementation of symbol extension and windowing techniques, where the transmission is extended for an extended period and shaped using a windowing function, both before and after a beam change, to reduce residual radiation and spectral regrowth during beam switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If beam switching is performed in wireless communication systems, then communication flexibility and adaptability are improved, but residual radiation and adjacent-channel interference increase due to undetermined RF front-end states
Solution Approach 1:
The patent applies preliminary action by extending the transmission duration before beam switching occurs. The transmitter continues transmitting using the previous beam configuration for an extended period (e.g., additional OFDM symbols) before transitioning to the new beam. This preliminary extension allows the RF front-end to stabilize and reduces residual radiation that would otherwise occur during abrupt beam switching.
Solution Approach 2:
The patent implements beforehand cushioning by applying windowing functions (such as Hann, Hamming, or Blackman windows) to the transmitted signal during the transition period. These windowing functions gradually reduce the signal amplitude at the boundaries of the extended transmission, cushioning the transition and minimizing spectral regrowth and adjacent-channel leakage ratio (ACLR) that would result from abrupt beam switching.
2Speed
If beam switching is performed quickly, then communication speed and responsiveness are improved, but spectral mask requirements are violated due to out-of-band emissions
Solution Approach 1:
The transmitter performs preliminary action by extending the transmission duration with the previous beam configuration before switching to the new beam. This extension period allows for proper signal conditioning and reduces the need for abrupt transitions that cause spectral regrowth and out-of-band emissions, thereby maintaining compliance with spectral mask requirements while enabling faster beam switching.
Solution Approach 2:
Windowing functions are applied beforehand to the extended transmission symbols to gradually taper the signal amplitude. This cushioning effect suppresses spectral regrowth and reduces out-of-band emissions that would otherwise violate spectral mask requirements during rapid beam switching operations.
3Object-generated harmful factors
If transmission duration is extended during beam switching, then residual radiation is reduced, but communication efficiency decreases due to longer transmission time
Solution Approach 1:
The patent applies partial action by extending the transmission duration only for the specific symbols immediately preceding beam switching, rather than extending all transmissions. Typically, only 1-2 OFDM symbols are extended with windowing applied, which is sufficient to reduce residual radiation while minimizing the impact on overall communication efficiency and throughput.
Solution Approach 2:
The patent changes the temporal parameter of the transmission by extending the duration of specific symbols during beam switching transitions. By modifying the time-domain characteristics of only the transition symbols (applying windowing and extension) while keeping other symbols at normal duration, the system reduces residual radiation without significantly impacting overall communication efficiency.
Data Source
AI summary
Apparatus, methods, and computer-readable media for facilitating symbol extension and windowing for beam switching are disclosed herein. An example method for wireless communication at transmitter includes performing a beam change for communicating with a wireless communication device. The example method also includes extending a transmission for an extended period of time based on the beam change. Additionally, the method includes applying a windowing function to the transmission during the extended period of time.