Del Peral-Rosado, López-Salcedo, Seco-Granados, Zanier, and Crisci, in their paper 'Joint maximum likelihood time-delay estimation for LTE positioning in multipath channels,' present a joint time-delay and channel estimator to assess the achievable positioning performance of the LTE networks, whose performance is heavily affected by radio multipath.
A joint time-frequency (TF) approach would be a better choice to efficiently process these signals.
To capture the Doppler frequency at various instances of time, a joint time-frequency analysis method is used.
This paper presents a joint time-delay and channel estimator to assess the achievable positioning performance of the Long Term Evolution (LTE) system in multipath channels.
In this block, a joint time-frequency offset and channel estimation has been implemented based on [24], and also including the enhanced version.
Only few methods are based on a joint spatial-frequency domain techniques [15, 16] or a joint time-frequency domain techniques [9, 17].
The first one is a joint frequency and channel estimator, while the second one is a joint time-delay and channel estimator.
A generalized WD that serves as a joint time-phase derivatives representation for monocomponent, constant-amplitude polynomial phase signals has been proposed in [42], based on decomposition of polynomial derivatives in terms of shifted versions of the involved polynomial.
Combining the features of OFDM and SCLD in the two domains, we can define a joint time-frequency domain feature function: z J = c 2 r ρ - 1 ; 0 c 2 r 0 ; ρK, (7).
The effective time, frequency, and joint time-frequency diversities obtainable at R1, R2, R3, R4, and R5 are shown in Figure 11. Figure 11 BER performance for (a) Joint time-frequency diversity gain, (b) Frequency diversity gain, and (c) time-diversity gain, for Scenario A. The diversity gains are obtained for the case of quadrature phase-shift keying (QPSK).
