9 problems

Let $N_f$ denote the pulse rate in a multipath spread-spectrum system, and let the bit-error rate (BER) be the performance measure of the jointly or individually optimal multiuser…

Consider an uncoded multiuser system with a large number of users, and let $N_f$ denote its pulse rate and its system BER denote the bit-error rate of the multiuser detector. For t…

Let $N_f$ denote the pulse rate, let $P_e\mid N_f$ be the BER of the optimal multiuser detector (MUD) at pulse rate $N_f$, and let $\rho\mid N_f$ denote the correlation between the…

Consider the soft nonlinear detection approaches studied for an $8\times 8$ MIMO system, excluding SDR and MOSIC. Finite-dimension suboptimality conjecture. These approaches share…

Consider a communication system with an independent and identically distributed random matrix and a postulated minimum-mean-square-error estimator. The decoupling conjecture. The p…

Consider a large-system linear estimation model with an arbitrary input distribution, without restricting the estimator to be linear. Spectral-efficiency decoupling conjecture. The…

Let $\tilde{u}_{\mathrm{un}}(x)$ be the non-uniform stationary solution described above for the spatially coupled system. Instability conjecture. We conjecture that…

Let a CDMA system use chip waveforms processed by a linear minimum mean-square-error (MMSE) multiuser detector. Sinc-pulse optimality conjecture. Sinc pulses are optimal for CDMA s…

Intermediate spectrum-overlap conjecture. Neither a completely orthogonal spectrum nor a completely overlapped spectrum is the best converged solution for decentralized spectrum sh…