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REVIEW 2 major objections 5 minor 43 references

Unknown data symbols can still sharpen multistatic target localization when receivers either average over them or reuse decoded ones as virtual pilots.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · grok-4.5

2026-07-14 14:11 UTC pith:RB7KYS23

load-bearing objection Solid multistatic ISAC paper: closed-form data-aided SPEBs for two receiver strategies, joint ρ–Rd design under rate constraints, and matching estimators that hit the bounds above low SNR. the 2 major comments →

arxiv 2607.10115 v1 pith:RB7KYS23 submitted 2026-07-11 eess.SP

Data-Aided Target Localization in Multistatic ISAC Systems With Communication Constraints

classification eess.SP
keywords integrated sensing and communicationmultistatic localizationdata-aided sensingOFDMCramér-Rao boundSPEBpilot-data allocationfinite-alphabet extension
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

In multistatic integrated sensing and communication, receivers see only the statistical law of the data symbols, not the symbols themselves. This paper shows that those symbols still carry localization information if they are handled correctly. One strategy marginalizes the random data and extracts angular information from the received covariance; the other decodes the data and reuses the recovered block as known virtual pilots that add mean-based ranging and angle information. Under OFDM, both strategies yield closed-form position error bounds that beat pilot-only sensing, and a joint design of pilot fraction and data covariance traces the best localization accuracy that remains once a required broadcast rate is met. Practical estimators that implement the two strategies approach the predicted bounds, and the same refined position also improves the channel estimate used for communication.

Core claim

Under OFDM multistatic ISAC, statistical marginalization of Gaussian data and reliable reuse of decoded data as virtual pilots both produce strictly better squared position error bounds than pilot-only sensing; the resulting joint SPEB-rate region is characterized by optimizing the pilot fraction and the data covariance under a broadcast-rate constraint.

What carries the argument

The equivalent Fisher information matrix (EFIM) of target position, written as a sum of rank-one directional intensities (bistatic delay, AOA, AOD). Theorems 1–3 and Corollaries 1–2 give the intensities for the pilot-only, marginalized-data, and decoded-data cases; the SPEB is then the closed-form inverse-trace of that EFIM, and communication-constrained optimization simply reshapes those intensities.

Load-bearing premise

The stronger scheme treats the whole data block as perfectly known once decoding succeeds, an idealization that holds only away from low signal-to-noise ratio and can fail when decoding errors feed back into the position update.

What would settle it

At moderate-to-high SNR with the same OFDM multistatic geometry, measure whether the two data-aided localizers produce position RMSE that tracks their theoretical SPEBs and lies strictly below the pilot-only SPEB; a collapse of that gap, or RMSE that never approaches the Scenario-2 bound even when decoding is near-perfect, would falsify the claimed data-aided gains.

Watch this falsifier — get emailed when new claim-graph text bears on it.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

2 major / 5 minor

Summary. The paper studies data-aided target localization in OFDM multistatic ISAC networks where sensing receivers do not know the transmitted data realizations. It introduces two receiver strategies: Scenario 1, which marginalizes unknown Gaussian data and extracts covariance-based angular information, and Scenario 2, a reliable-recovery benchmark that reuses correctly decoded data as virtual pilots. Closed-form channel-domain EFIMs and position SPEBs are derived (Theorems 1–3, Corollaries 1–2, Proposition 1), the achievable ergodic broadcast rate is characterized under pilot-based channel estimation, and a joint pilot-fraction and data-covariance design problem is solved under a rate constraint to trace the SPEB–rate region. Two matched localization algorithms are developed, a finite-alphabet extension is sketched, and simulations confirm the ordering P2 < P1 < NDA and that practical RMSEs approach the PEBs above a low-SNR threshold.

Significance. If the results hold, the paper gives a unified multistatic localization framework that quantifies how much position information unknown communication symbols can contribute under different receiver processing strategies and under an explicit rate constraint. The closed-form EFIMs, the geometric intensity–direction decomposition, and the joint ρ–Rd design are concrete tools for SPEB–rate tradeoff analysis beyond monostatic or pilot-only baselines. Strengths include first-principles complex-Gaussian FIM derivations with Schur complements (Appendices I–IV), a compact SPEB inversion for rank-one directional EFIMs (Proposition 1), matched estimators that approach the bounds in simulation, and transparent scoping of Scenario 2 as a reliable-recovery benchmark rather than an all-SNR claim. These contributions are relevant to ISAC transceiver design and performance characterization in multistatic networks.

major comments (2)
  1. Scenario 2 is repeatedly used as the upper-bound data-aided sensing regime (Theorems 3, Corollary 2, Figs. 3–5, 7), yet it is defined under error-free recovery of the full data block (footnote 4; Remark 7; §V-B). Fig. 7 shows a clear low-SNR RMSE departure and residual gap even at moderate SNR due to data-estimation errors. The central SPEB–rate claims remain valid as a benchmark, but the manuscript should more sharply separate the information-theoretic known-data bound from the practical alternating MAP estimator, and quantify (even approximately) how residual symbol error rate degrades the effective intensities in (35) or the SPEB in (36).
  2. The abstract and contribution list claim an extension to finite-alphabet signaling (§III-D), but that section only sketches the Gaussian-mixture likelihood (44) and notes exponential complexity, without closed-form FIM, optimized SPEB–rate curves, or Monte Carlo results. Either provide at least one finite-alphabet numerical case (e.g., QPSK SISO/MIMO SPEB vs. SNR or rate) that supports the claimed delay-information retention under discrete rotational symmetries, or demote the finite-alphabet material to a brief outlook so the abstract matches the delivered results.
minor comments (5)
  1. Notation density is high: η, ξ, θk, ϑk, and multiple intensity symbols (λ, μ̃, γ) appear in close succession. A short notation table or a one-paragraph roadmap at the start of §III would help.
  2. In §IV-B, Algorithm 1 is shown to monotonically decrease SPEB, but stationarity of (ρ, Rd) is only checked numerically (Fig. 6). A brief remark on when block-SCA guarantees apply under the rate-feasible set C(ρ) would strengthen the optimization section.
  3. Fig. 5 plots 1/SPEB vs. rate with optimized covariance; the caption and text should state more clearly whether Rd is re-optimized at each rate point or fixed to one target-directed beam while only ρ is swept.
  4. SISO special case (Corollary 2) is clean; a short numerical SISO panel (even in the appendix) would make the pilot-only vs. known-data contrast more visible for readers less focused on MIMO angular gains.
  5. Minor typos and style: “Cramér-Rao” is inconsistently spaced; “beampatterna H_t” in Theorem 2 needs a space; arXiv-style “e-prints” references could be updated if journal versions exist.

Circularity Check

0 steps flagged

No significant circularity: SPEB/rate limits are derived from the observation model via standard complex-Gaussian FIM rules, not from fitted inputs or load-bearing self-citation chains.

full rationale

The paper's central claims (Theorems 1–3, Corollaries 1–2, joint SPEB-rate region under rate constraints) follow by applying the standard complex-Gaussian FIM formula (Eq. 7) to the OFDM multistatic observation model (Eqs. 4–6), then eliminating nuisance amplitudes via Schur complement and mapping channel parameters to position via the geometric Jacobian of §III-A. Scenario 1's covariance-only angular contribution and Scenario 2's full-frame mean contribution are direct consequences of whether data symbols are marginalized or treated as known; neither quantity is fitted to data and then re-presented as a prediction. The SPEB definition P = tr(J_e^{-1}) and the ergodic-rate metric are independent external performance measures. Self-citations (e.g., Shen & Win SPEB/geometry framework [34], [35]) supply standard localization machinery that is externally published and widely used; they do not force the multistatic data-aided gains, which are derived from the present observation model. Scenario 2 is explicitly scoped as a reliable-recovery benchmark rather than an all-SNR claim. No uniqueness theorem is imported to forbid alternatives, no ansatz is smuggled in as a first-principles result, and no fitted parameter is renamed a prediction. The derivation chain is self-contained against its own model assumptions.

Axiom & Free-Parameter Ledger

2 free parameters · 6 axioms · 0 invented entities

The central SPEB-rate claims rest on standard complex-Gaussian FIM calculus, the OFDM multistatic geometric model, and the two receiver processing strategies. Free parameters are ordinary design variables (ρ, Rd) optimized under constraints, not fitted constants. No new physical entities are postulated.

free parameters (2)
  • pilot fraction ρ
    Design variable optimized in (45)–(46); not fitted to external data but chosen to trade SPEB against rate.
  • data covariance Rd
    MIMO design variable with tr(Rd)=1, Rd ⪰ 0; optimized by proximal SCA, not a data-fit constant.
axioms (6)
  • standard math Complex circularly-symmetric Gaussian observation model yields the standard FIM formula (7).
    Invoked throughout Section III and Appendices I–IV.
  • domain assumption Data symbols are i.i.d. zero-mean Gaussian with known covariance Rd (or finite alphabet later).
    Stated in Section II-A; enables closed-form covariance FIM for Scenario 1.
  • domain assumption Single point target; direct path and static clutter already removed or absorbed into noise.
    Remark after (4) and system model in Section II.
  • domain assumption Transmitter and receiver positions known; target position is the sole unknown of interest.
    Section II-A geometry.
  • ad hoc to paper Scenario 2 assumes error-free recovery of the data block so that it acts as known waveform.
    Explicit reliable-recovery benchmark (footnote 4, Theorem 3); acknowledged as idealization.
  • domain assumption Orthogonal pilots on every subcarrier with Rp = Mt^{-1} I.
    Condition (2); used to obtain diagonal pilot EFIM.

pith-pipeline@v1.1.0-grok45 · 31313 in / 2674 out tokens · 30194 ms · 2026-07-14T14:11:09.003100+00:00 · methodology

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read the original abstract

Integrated sensing and communication (ISAC) enables future wireless networks to perform sensing and communication (S&C) over a shared waveform. In multistatic ISAC systems, however, the sensing receivers do not know the realizations of transmitted data symbols, making it challenging to exploit communication signals for sensing. In this paper, we propose a data-aided framework for target localization with two receiver strategies, namely statistical data-aided sensing and joint data-aided sensing and decoding, where the former marginalizes the random unknown data symbols and the latter reuses the reliably decoded data symbols as known virtual pilots. Under orthogonal frequency division multiplexing (OFDM) signaling, we derive the performance limits for target localization in both strategies and adopt the achievable ergodic data rate as the communication metric. Then, we formulate a joint time-allocation and transmit data-covariance design problem for target localization under communication constraints, which characterizes the joint S&C bound and quantifies the sensing gain provided by data symbols. In addition, we develop two target localization algorithms that implement the proposed data-aided receiver processing, and extend the framework to finite-alphabet signaling. Simulation results validate theoretical analysis and the effectiveness of the proposed data-aided schemes.

Figures

Figures reproduced from arXiv: 2607.10115 by Chao Ge, Na Zhao, Xiao Shen, Yuan Shen, Ziping Lu.

Figure 1
Figure 1. Figure 1: Multistatic ISAC system geometry and data-aided sensing schemes. Scenario 1 treats RU data symbols as nuisance parameters, whereas Scenario 2 relies on data recovery and exploits recovered data symbols for sensing. DK and RU refer to deterministic known and random unknown, respectively. to compensate for waveform uncertainty at the transmitter. Accounting for estimation coupling at the receiver, [25] deriv… view at source ↗
Figure 2
Figure 2. Figure 2: Spatial information directions for multistatic target localization: the [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: SPEB and broadcast data rate versus pilot fraction ρ at 5 dB under a fixed data covariance. which can be solved by alternating between data-waveform recovery and known-waveform localization, following the joint channel-estimation and data-detection principle in [29], [43]. Given (p (t) , {α (t) k }), the common data update is Sˆ (t) d ∈ arg min Sd∈Cd X K k=1 [PITH_FULL_IMAGE:figures/full_fig_p010_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: SPEB and broadcast data rate versus SNR for NDA, DA S1, and DA S2 under fixed ρ = 0.32 and a fixed Rd. estimators. Unless otherwise stated, we consider a multistatic network with one transmitter, one point target, and K = 3 receivers, located at pt = [0, 0]T , p = [18, 14]T , pr,1 = [30, 2]T , pr,2 = [5, 30]T , and pr,3 = [34, 26]T in meters. The propagation speed is c = 3 × 108 m/s, the subcarrier spacing… view at source ↗
Figure 6
Figure 6. Figure 6: Convergence of Algorithm 1 from isotropic and random feasible [PITH_FULL_IMAGE:figures/full_fig_p011_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Position RMSE and PEB versus SNR at ρ = 0.1 for the NDA, DA S1, and DA S2 localizers. 12 dB, where Rd is fixed to the target-directed beam obtained from Algorithm 1’s joint optimization and the pilot fraction is swept over its feasible integer values. The gray, blue, and red fillings denote the feasible areas below the NDA, DA S1, and DA S2 bound curves, respectively. The NDA curve reflects the pilot-only … view at source ↗

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Works this paper leans on

43 extracted references · 2 linked inside Pith

  1. [1]

    Sensing with communication signals: From information theory to signal processing,

    F. Liu, Y .-F. Liu, Y . Cui, C. Masouros, J. Xu, T. X. Han, S. Buzzi, Y . C. Eldar, and S. Jin, “Sensing with communication signals: From information theory to signal processing,”IEEE J. Sel. Areas Commun., vol. 44, pp. 1–30, Oct. 2025

  2. [2]

    ISAC with UWB: Reliable decoupling and target sensing,

    F. Liu, T. Zhang, Z. Zhang, Y . Shen, and Q. Zhang, “ISAC with UWB: Reliable decoupling and target sensing,”IEEE Trans. Wireless Commun., vol. 23, pp. 15 957–15 972, Nov. 2024

  3. [3]

    Cooperative ISAC-empowered low-altitude economy,

    J. Tang, Y . Yu, C. Pan, H. Ren, D. Wang, J. Wang, and X. You, “Cooperative ISAC-empowered low-altitude economy,”IEEE Trans. Wireless Commun., vol. 24, no. 5, pp. 3837–3853, May 2025

  4. [4]

    Cooperative tracking by multi-agent systems using signals of opportunity,

    Y . Wang, Y . Wu, and Y . Shen, “Cooperative tracking by multi-agent systems using signals of opportunity,”IEEE Trans. Commun., vol. 68, no. 1, pp. 93–105, Jan. 2020

  5. [5]

    Toward ISAC- empowered vehicular networks: Framework, advances, and opportunities,

    Z. Du, F. Liu, Y . Li, W. Yuan, Y . Cui, and Z. Zhang, “Toward ISAC- empowered vehicular networks: Framework, advances, and opportunities,” IEEE Wireless Commun. Mag., vol. 32, no. 2, pp. 222–229, Apr. 2025

  6. [6]

    MU-MIMO com- munications with MIMO radar: From co-existence to joint transmission,

    F. Liu, C. Masouros, A. Li, H. Sun, and L. Hanzo, “MU-MIMO com- munications with MIMO radar: From co-existence to joint transmission,” IEEE Trans. Wireless Commun., vol. 17, no. 4, pp. 2755–2770, Feb. 2018

  7. [7]

    On the fundamental tradeoff of integrated sensing and communications under Gaussian channels,

    Y . Xiong, F. Liu, Y . Cui, W. Yuan, T. X. Han, and G. Caire, “On the fundamental tradeoff of integrated sensing and communications under Gaussian channels,”IEEE Trans. Inf. Theory, vol. 69, no. 9, pp. 5723– 5751, Sep. 2023

  8. [8]

    Fundamental tradeoff of bistatic ISAC under Gaussian fading channels at finite blocklength,

    X. Shen, Z. Lu, N. Zhao, H. Zhao, and Y . Shen, “Fundamental tradeoff of bistatic ISAC under Gaussian fading channels at finite blocklength,” IEEE Trans. Inf. Theory, vol. 72, no. 2, pp. 1176–1200, Feb. 2026. 15

  9. [9]

    Fundamental trade-offs in monostatic ISAC: A holistic investigation toward 6G,

    M. F. Keskin, M. M. Mojahedian, J. O. Lacruz, C. Marcus, O. Eriksson, A. Giorgetti, J. Widmer, and H. Wymeersch, “Fundamental trade-offs in monostatic ISAC: A holistic investigation toward 6G,”IEEE Trans. Wireless Commun., vol. 24, pp. 7856–7873, Sep. 2025

  10. [10]

    Joint transmit beamforming for multiuser MIMO communications and MIMO radar,

    X. Liu, T. Huang, N. Shlezinger, Y . Liu, J. Zhou, and Y . C. Eldar, “Joint transmit beamforming for multiuser MIMO communications and MIMO radar,”IEEE Trans. Signal Process., vol. 68, pp. 3929–3944, Jun. 2020

  11. [11]

    Joint transmit and receive beamforming design for integrated sensing and communication,

    N. Zhao, Y . Wang, Z. Zhang, Q. Chang, and Y . Shen, “Joint transmit and receive beamforming design for integrated sensing and communication,” IEEE Commun. Lett., vol. 26, no. 3, pp. 662–666, Jan. 2022

  12. [12]

    Reshaping the ISAC tradeoff under OFDM signaling: A probabilistic constellation shaping approach,

    Z. Du, F. Liu, Y . Xiong, T. X. Han, Y . C. Eldar, and S. Jin, “Reshaping the ISAC tradeoff under OFDM signaling: A probabilistic constellation shaping approach,”IEEE Trans. Signal Process., vol. 72, pp. 4782–4797, Sep. 2024

  13. [13]

    CP-OFDM achieves the lowest average ranging sidelobe under QAM/PSK constellations,

    F. Liu, Y . Zhang, Y . Xiong, S. Li, W. Yuan, F. Gao, S. Jin, and G. Caire, “CP-OFDM achieves the lowest average ranging sidelobe under QAM/PSK constellations,”IEEE Trans. Inf. Theory, vol. 71, no. 9, pp. 6950–6968, Sep. 2025

  14. [14]

    Joint target localization and data detection in bistatic ISAC networks,

    N. Zhao, Q. Chang, X. Shen, Y . Wang, and Y . Shen, “Joint target localization and data detection in bistatic ISAC networks,”IEEE Trans. Commun., vol. 73, no. 5, pp. 3531–3546, May 2025

  15. [15]

    Integrated sensing and communication receiver design for OTFS-based MIMO system: A unified variational inference framework,

    N. Wu, H. Li, D. He, A. Nallanathan, and T. Q. S. Quek, “Integrated sensing and communication receiver design for OTFS-based MIMO system: A unified variational inference framework,”IEEE J. Sel. Areas Commun., vol. 43, no. 4, pp. 1339–1353, Apr. 2025

  16. [16]

    Limited feedforward waveform design for OFDM dual-functional radar-communications,

    M. F. Keskin, V . Koivunen, and H. Wymeersch, “Limited feedforward waveform design for OFDM dual-functional radar-communications,” IEEE Trans. Signal Process., vol. 69, pp. 2955–2970, Apr. 2021

  17. [17]

    MIMO integrated sensing and communication: CRB-rate tradeoff,

    H. Hua, T. X. Han, and J. Xu, “MIMO integrated sensing and communication: CRB-rate tradeoff,”IEEE Trans. Wireless Commun., vol. 23, pp. 2839–2854, Apr. 2024

  18. [18]

    Fundamental CRB-rate tradeoff in multi-antenna ISAC systems with information multicasting and multi-target sensing,

    Z. Ren, Y . Peng, X. Song, Y . Fang, L. Qiu, L. Liu, D. W. K. Ng, and J. Xu, “Fundamental CRB-rate tradeoff in multi-antenna ISAC systems with information multicasting and multi-target sensing,”IEEE Trans. Wireless Commun., vol. 23, pp. 3870–3885, Apr. 2024

  19. [19]

    Fundamental limits for ISAC: CRB-rate bound and bound-achieving input distribution,

    Y . Guo, Y . Gu, M. Wang, and B. Xia, “Fundamental limits for ISAC: CRB-rate bound and bound-achieving input distribution,”IEEE Trans. Wireless Commun., vol. 25, pp. 5605–5621, Oct. 2025

  20. [20]

    A framework for uplink ISAC receiver designs: Performance analysis and algorithm development,

    Z. Yu, H. Ren, C. Pan, G. Zhou, D. Wang, C. Yuen, and J. Wang, “A framework for uplink ISAC receiver designs: Performance analysis and algorithm development,”arXiv e-prints, arXiv:2503.02647, Mar. 2025

  21. [21]

    Cooperative ISAC networks: Performance analysis, scaling laws, and optimization,

    K. Meng, C. Masouros, A. P. Petropulu, and L. Hanzo, “Cooperative ISAC networks: Performance analysis, scaling laws, and optimization,” IEEE Trans. Wireless Commun., vol. 24, pp. 877–892, Feb. 2025

  22. [22]

    Joint communication and localization in millimeter wave networks,

    G. Kwon, A. Conti, H. Park, and M. Z. Win, “Joint communication and localization in millimeter wave networks,”IEEE J. Sel. Topics Signal Process., vol. 15, no. 6, pp. 1439–1454, Nov. 2021

  23. [23]

    Fundamental MMSE-rate performance limits of integrated sensing and communication systems,

    Z. Wang and X. Wang, “Fundamental MMSE-rate performance limits of integrated sensing and communication systems,”arXiv e-prints, arXiv:2501.01053, Jan. 2025

  24. [24]

    CRB-rate tradeoff for bistatic ISAC with Gaussian information and deterministic sensing signals,

    X. Song, X. Yu, J. Xu, and D. W. K. Ng, “CRB-rate tradeoff for bistatic ISAC with Gaussian information and deterministic sensing signals,”IEEE Trans. Wireless Commun., vol. 25, pp. 11 768–11 782, Feb. 2026

  25. [25]

    On the trade-off between angle of arrival and symbol estimation in bistatic ISAC systems using unitary signaling,

    S. Fodor, G. Fodor, and M. Telek, “On the trade-off between angle of arrival and symbol estimation in bistatic ISAC systems using unitary signaling,”IEEE Trans. Commun., vol. 73, pp. 5328–5343, Jul. 2025

  26. [26]

    Data-aided channel estimation in large antenna systems,

    J. Ma and L. Ping, “Data-aided channel estimation in large antenna systems,”IEEE Trans. Signal Process., vol. 62, no. 12, pp. 3111–3124, Jun. 2014

  27. [27]

    Fundamental limits via CRB of semi-blind channel estimation in Massive MIMO systems,

    X. Zhang, A. Kammoun, and M.-S. Alouini, “Fundamental limits via CRB of semi-blind channel estimation in Massive MIMO systems,”IEEE Trans. Signal Process., vol. 73, pp. 3572–3587, Aug. 2025

  28. [28]

    Exploiting both pilots and data payloads for integrated sensing and communications,

    C. Xu, X. Yu, F. Liu, and S. Jin, “Exploiting both pilots and data payloads for integrated sensing and communications,”IEEE Trans. Wireless Commun., vol. 25, pp. 5573–5586, Oct. 2025

  29. [29]

    Bridging the gap via data-aided sensing: Can bistatic ISAC converge to genie performance?

    M. F. Keskin, S. Mura, M. Mizmizi, D. Tagliaferri, and H. Wymeersch, “Bridging the gap via data-aided sensing: Can bistatic ISAC converge to genie performance?” inProc. IEEE Radar Conf. (RadarConf), Krakow, Poland, Oct. 2025

  30. [30]

    Communication-assisted sensing in 6G networks,

    F. Dong, F. Liu, S. Lu, Y . Xiong, Q. Zhang, Z. Feng, and F. Gao, “Communication-assisted sensing in 6G networks,”IEEE J. Sel. Areas Commun., vol. 43, pp. 1371–1386, Apr. 2025

  31. [31]

    Joint localization and orientation estimation in millimeter-wave MIMO OFDM systems via atomic norm minimization,

    J. Li, M. F. D. Costa, and U. Mitra, “Joint localization and orientation estimation in millimeter-wave MIMO OFDM systems via atomic norm minimization,”IEEE Trans. Signal Process., vol. 70, pp. 4252–4264, Aug. 2022

  32. [32]

    Joint delay and doppler estimation for passive sensing with direct-path interference,

    X. Zhang, H. Li, J. Liu, and B. Himed, “Joint delay and doppler estimation for passive sensing with direct-path interference,”IEEE Trans. Signal Process., vol. 64, no. 3, pp. 630–640, Oct. 2015

  33. [33]

    Conditional and unconditional Cram ´er-Rao bounds for near-field localization in bistatic MIMO radar systems,

    L. Khamidullina, I. Podkurkov, and M. Haardt, “Conditional and unconditional Cram ´er-Rao bounds for near-field localization in bistatic MIMO radar systems,”IEEE Trans. Signal Process., vol. 69, pp. 3220– 3234, May 2021

  34. [34]

    Fundamental limits of wideband localization – Part I: A general framework,

    Y . Shen and M. Z. Win, “Fundamental limits of wideband localization – Part I: A general framework,”IEEE Trans. Inf. Theory, vol. 56, no. 10, pp. 4956–4980, Oct. 2010

  35. [35]

    Power optimization for network localization,

    Y . Shen, W. Dai, and M. Z. Win, “Power optimization for network localization,”IEEE/ACM Trans. Netw., vol. 22, no. 4, pp. 1337–1350, Aug. 2014

  36. [36]

    How much training is needed in multiple-antenna wireless links?

    B. Hassibi and B. M. Hochwald, “How much training is needed in multiple-antenna wireless links?”IEEE Trans. Inf. Theory, vol. 49, no. 4, pp. 951–963, Apr. 2013

  37. [37]

    Boyd and L

    S. Boyd and L. Vandenberghe, Convex Optimization. Cambridge, U.K.: Cambridge Univ. Press, 2004

  38. [38]

    A unified convergence analysis of block successive minimization methods for nonsmooth optimization,

    M. Razaviyayn, M. Hong, and Z.-Q. Luo, “A unified convergence analysis of block successive minimization methods for nonsmooth optimization,” SIAM Journal on Optimization, vol. 23, no. 2, pp. 1126–1153, 2013

  39. [39]

    Parallel and distributed methods for constrained nonconvex optimization—part I: Theory,

    G. Scutari, F. Facchinei, L. Lampariello, and P. Song, “Parallel and distributed methods for constrained nonconvex optimization—part I: Theory,”IEEE Trans. Signal Process., vol. 65, no. 8, pp. 1929–1944, Apr. 2017

  40. [40]

    Majorization-minimization algo- rithms in signal processing, communications, and machine learning,

    Y . Sun, P. Babu, and D. P. Palomar, “Majorization-minimization algo- rithms in signal processing, communications, and machine learning,” IEEE Trans. Signal Process., vol. 65, no. 3, pp. 794–816, Feb. 2017

  41. [41]

    Performance study of conditional and unconditional direction-of-arrival estimation,

    P. Stoica and A. Nehorai, “Performance study of conditional and unconditional direction-of-arrival estimation,”IEEE Trans. Acoust., Speech, Signal Process., vol. 38, no. 10, pp. 1783–1795, Oct. 1990

  42. [42]

    Direct target localization with an active radar network,

    J. Bosse, O. Krasnov, and A. Yarovoy, “Direct target localization with an active radar network,”Signal Process., vol. 125, pp. 21–35, Jan. 2016

  43. [43]

    Efficient joint maximum-likelihood channel estimation and signal detection,

    H. Vikalo, B. Hassibi, and P. Stoica, “Efficient joint maximum-likelihood channel estimation and signal detection,”IEEE Trans. Wireless Commun., vol. 5, no. 7, pp. 1838–1845, Jul. 2006