HE-LTF Alignment in 802.11ax OFDMA Networks

The patent applies preliminary action by extending the long training field duration before data transmission begins. The access point determines the maximum symbol duration among all users and extends each user's training field to match this maximum duration, ensuring all training fields are aligned in time before the actual data communication starts. This preliminary extension resolves the alignment issue while maintaining the benefits of varying resource block allocations.

The patent applies dynamics by making the training field duration adjustable and user-specific. Each user's training field is extended to the maximum duration dynamically based on their allocated resource blocks and symbol duration. This dynamic extension ensures alignment without forcing all users to use the same fixed duration, allowing the system to adapt to different user requirements while maintaining synchronization.

The patent applies parameter changes by modifying the duration parameter of existing long training fields rather than adding completely new symbols. The access point adjusts the symbol duration parameter of each user's training field to match the maximum duration in the system. This parameter change approach achieves better channel estimation accuracy through extended observation time while minimizing overhead compared to adding entirely new training symbols.