Introduction - If you have any usage issues, please Google them yourself
The use of antenna arrays in wireless communications
makes it possible to estimate the directions of arrival (DOAs)
of impinging waveforms. The latter can be exploited to enhance
channel estimation accuracy or as an input for advanced mobile
positioning systems. In this paper, we consider the uplink of a
multicarrier code-division multiple-access (MC-CDMA) network
in which the base station is endowed with multiple receiving antennas
arranged in a uniform linear array. Transmission takes place
over a multipath channel, and the goal is the joint estimation of
the channel responses and DOAs of the uplink signals. In doing so,
we follow a maximum-likelihood (ML) approach and assume that
users transmit orthogonal training sequences to facilitate the task
of separating the signals. This way, all unknown parameters are
estimated independently of each other with affordable complexity.
Theoretical analysis and computer simulations are used to assess
the performance of the propose