# 📡 PL Tx Subsystem (Pulse Generator)

## Overview

The Tx subsystem implements a pulse-based LFM chirp generator using a DDS/NCO architecture.

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## Architecture

TxPulseStart → pulse_gen_ctrl → tx_active → NCO → Output

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## Chirp Generation

Δφ[n] = Δφ[n−1] + step  
φ[n]  = φ[n−1] + Δφ[n]

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## Parameterization

- Fc (center frequency)
- B (bandwidth)

Derived:
f_start = Fc − B/2  
step    = B / (N − 1)

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## Pulse Timing

|<------ PRI ------>|
|<-- pulse -->| idle |

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## Trigger

Controlled via TxPulseStart (from PS subsystem)

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## 🔗 Related Components

- [PS Subsystem](ps_subsystem.md)
- [PL Rx Subsystem](pl_rx_subsystem.md)