  Millimeter wave (mmWave) and sub-THz communications, foreseen for sixth
generation (6G), suffer from high propagation losses which affect the network
coverage. To address this point, smart entities such as network-controlled
repeaters (NCRs) have been considered as cost-efficient solutions for coverage
extension. NCRs, which have been standardized in 3rd generation partnership
project Release 18, are radio frequency repeaters with beamforming capability
controlled by the network through side control information. Another challenge
raised by the adoption of high frequency bands is the use of large bandwidths.
Here, a common configuration is to divide a large frequency band into multiple
smaller subbands. In this context, we consider a scenario with NCRs where
signaling related to measurements used for radio resource management is
transmitted in one subband centered at frequency $f_c$ and data transmission is
performed at a different frequency $f_c + \Delta f$ based on the measurements
taken at $f_c$. Here, a challenge is that the array radiation pattern can be
frequency dependent and, therefore, lead to beam misalignment, called beam
squinting. We characterize beam squinting in the context of subband operation
and propose a solution where the beam patterns to be employed at a given
subband can be adjusted/compensated to mitigate beam squinting. Our results
show that, without compensation, the perceived signal to
interference-plus-noise ratio (SINR) and so the throughput can be substantially
decreased due to beam squinting. However, with our proposed compensation
method, the system is able to support NCR subband signaling operation with
similar performance as if signaling and data were transmitted at the same
frequency.
