Constant-Amplitude Precoding for Downlink OOB Null Steering

The patent applies parameter changes by dynamically adjusting the frequency cutoff point of the band filter based on the operational phase. During the first phase (3.82-4 GHz), the system uses a higher cutoff frequency that allows operation while maintaining acceptable interference levels, and transitions to a lower cutoff frequency (280 MHz) in the second phase to meet stringent regulatory requirements. This phased parameter adjustment resolves the contradiction between immediate operational needs and long-term regulatory compliance.

The system implements dynamic filter configuration where the band filter cutoff frequency is not fixed but adapts based on the deployment phase. The network node can switch between different filter settings (first phase cutoff at 4 GHz, second phase cutoff at 280 MHz) to optimize performance for current operational requirements while preparing for future regulatory constraints, thus resolving the contradiction between immediate usability and future compliance.

The patent implements a dynamic filter configuration where the band filter cutoff frequency adapts based on the deployment phase. During the first phase, the system uses a higher cutoff frequency (4 GHz) that allows operators to deploy without immediate hardware changes. When additional spectrum becomes available in the second phase, the system can transition to a lower cutoff frequency (280 MHz) without requiring physical radio swaps, thus reducing deployment costs while maintaining interference mitigation.

The system performs preliminary configuration with a more lenient filter setting (4 GHz cutoff) during the first phase, allowing operators to deploy infrastructure in advance. This preliminary setup prepares the network for future expansion while avoiding premature hardware commitments. When the second phase arrives with additional spectrum requirements, the filter parameter is simply adjusted rather than requiring physical radio replacements, thereby reducing overall deployment cost.

Instead of using complex digital pre-distorters, the patent employs a simpler approach by adjusting the frequency cutoff parameter of the band filter. This parameter-based solution achieves OOB interference mitigation without requiring complex signal processing algorithms or additional hardware components, thus resolving the contradiction between interference reduction and implementation complexity.

The patent uses a simple, easily implementable filter parameter configuration rather than expensive and complex digital pre-distortion systems. The solution leverages existing hardware capabilities by simply adjusting filter cutoff frequencies, avoiding the need for costly additional equipment or complex software algorithms, thereby reducing implementation complexity while maintaining effectiveness.

The patent applies local quality by implementing frequency-selective filtering that targets specific frequency bands (3.82-4 GHz during first phase, and 280 MHz during second phase) rather than reducing power across the entire cell. This localized approach to interference mitigation allows the system to reduce OOB interference in specific frequency ranges while maintaining full power transmission in other bands, thus preserving cell coverage and throughput.

The system segments the frequency spectrum into different bands and applies different power control strategies to each. During the first phase, the 3.82-4 GHz band is filtered with higher cutoff to reduce OOB interference while other bands continue at full power. In the second phase, the 280 MHz band is targeted for filtering. This segmentation allows selective interference mitigation without uniformly reducing cell power, thereby maintaining productivity.