Multi-Domain Optimization Framework for ISAC

This repository contains the MATLAB implementation for the paper:

R. Liu, M. Li, M. Zafari, B. Ottersten, and A. L. Swindlehurst, "Multi-domain optimization framework for ISAC: From electromagnetic shaping to network cooperation," IEEE Wireless Communications, under revision.

📖 Abstract

Integrated sensing and communication (ISAC) has emerged as a key feature for sixth-generation (6G) networks, providing an opportunity to meet the dual demands of communication and sensing. Existing ISAC research primarily focuses on baseband optimization at individual access points, with limited attention to the roles of electromagnetic (EM) shaping and network-wide coordination. The intricate interdependencies between these domains remain insufficiently explored, leaving their full potential for enhancing ISAC performance largely untapped. To bridge this gap, we consider multi-domain ISAC optimization integrating EM shaping, baseband processing, and network cooperation strategies that facilitate efficient resource management and system-level design. We analyze the fundamental trade-offs between these domains and offer insights into domain-specific and cross-domain strategies contributing to ISAC performance and efficiency. We then conduct a case study demonstrating the effectiveness of joint multi-domain optimization. Finally, we discuss key challenges and future research directions to connect theoretical advancements and practical ISAC deployments. This work paves the way for intelligent and scalable ISAC architectures, providing critical insights for their seamless integration into next-generation wireless networks.

📚 Citation

If you use this simulation code package in any way, please cite our paper:

BibTeX Format

@article{liu2025multidomain,
  title={Multi-domain optimization framework for {ISAC}: From electromagnetic shaping to network cooperation},
  author={Liu, Rang and Li, Ming and Zafari, Mehdi and Ottersten, Bj{\"o}rn and Swindlehurst, A. Lee},
  journal={IEEE Wireless Communications},
  year={2025},
  note={Under revision},
  url={https://arxiv.org/abs/2506.16011v1}
}

IEEE Format

R. Liu, M. Li, M. Zafari, B. Ottersten, and A. L. Swindlehurst, "Multi-domain optimization framework for ISAC: From electromagnetic shaping to network cooperation," IEEE Wireless Communications, under revision, 2025. [Online]. Available: https://arxiv.org/abs/2506.16011v1

Plain Text Format

Rang Liu, Ming Li, Mehdi Zafari, Björn Ottersten, and A. Lee Swindlehurst. "Multi-domain optimization framework for ISAC: From electromagnetic shaping to network cooperation." IEEE Wireless Communications (under revision), 2025.

🔧 Requirements

Software Platform

MATLAB R2023b or later (compatibility issues may arise with earlier versions)
CVX - Convex optimization toolbox for solving SDP problems
Manopt - Optimization on manifolds toolbox for non-convex problems

Installation

Download and install MATLAB R2023b or later
Install CVX toolbox
Install Manopt toolbox

📁 Code Structure

Main Scripts

main_power_SINR.m - Generates Figure 5(a): Radar SINR performance vs. transmit power
- Sweeps transmit power from 30 to 50 dBm
- Compares five optimization schemes
- Monte Carlo simulation with 100 trials
main_SR_SINR.m - Generates Figure 5(b): Radar SINR vs. communication sum-rate trade-off
- Analyzes sensing-communication trade-offs
- Fixed power at 50 dBm
- Varies sum-rate requirement from 0 to 100 bps/Hz

Optimization Functions

Core Optimization Algorithms

opt_prop.m - Proposed cross-domain joint optimization
- Jointly optimizes: AP selection, subcarrier allocation, beamforming, and polarization
- Integrates EM, baseband, and network domains
opt_radar.m - Radar-only benchmark
- Maximizes radar SINR without communication constraints
- Upper bound for sensing performance

Domain-Specific Optimization

opt_BP.m - Baseband processing domain only
- Fixed AP selection and polarization
- Optimizes subcarrier allocation and beamforming
opt_BP_EM.m - Joint baseband and EM-domain
- Fixed AP selection
- Optimizes subcarrier allocation, beamforming, and polarization
opt_BP_NC.m - Joint baseband and network-domain
- Fixed polarization
- Optimizes AP selection, subcarrier allocation, and beamforming

Channel Generation Functions

generate_ap_to_ap_channels.m - Inter-AP interference channels (G_ijn)
generate_ap_to_ue_channels.m - AP-to-UE communication channels (H_jnk)
generate_target_scattering.m - Radar target scattering matrix (Φ_ij)

Resource Allocation Functions

allocate_ap.m - AP role assignment (transmit/receive selection)
allocate_subcarrier.m - Frequency resource allocation between sensing and communication

Compute Auxiliary Variables

compute_c.m
compute_eta.m
compute_He.m
compute_t.m

Initialization Functions

initialize_MRT_grouped.m - Maximum ratio transmission initialization
initialize_Wr_grouped.m - Radar beamforming initialization

Update Functions

update_pk.m - User polarization
update_rPj.m - Receive AP polarization
update_tPj.m - Transmit AP polarization
update_u.m - Receive filter
update_W.m - Transmit beamforming

Data and Visualization

data_power.mat - Saved simulation results for power analysis
data_sr.mat - Saved simulation results for sum-rate analysis
power.fig / power.eps - Figure 5(a) outputs
SR.fig / SR.eps - Figure 5(b) outputs

🎯 Key Features