A method for automatic gain control in a wireless communication network for power grid control, the wireless communication network employing time based scheduling of packets, the method being performed by a packet receiver in the wireless communication network, the method comprising: receiving a packet from a packet transmitter (200b, 200c,..., 200N), wherein the packet comprises a preamble, wherein the preamble is composed of a single orthogonal frequency-division multiplexing, OFDM, symbol and represented by a sequence of samples; applying variable gain amplitude control to the sequence of samples, thereby resulting in a sequence of variable gain amplitude controlled samples; applying automatic gain control to the sequence of variable gain amplitude controlled samples to produce an automatic gain control value, wherein the automatic gain control involves applying (S106b) a low-pass filter, LPF, to the sequence of variable gain amplitude controlled samples, wherein the LPF is selected from a bank of LPFs, wherein which LPF to apply depends on, according to the time based scheduling, from which packet transmitter (200b, 200c,..., 200N) the packet is received; and feeding the automatic gain control value as a control signal to be used during the variable gain amplitude control when applied to a next packet from the same packet transmitter (200b, 200c,..., 200N), wherein the automatic gain control value depends, via the LPF, on a previous automatic gain control value for the same packet transmitter (200b, 200c,..., 200N), and wherein the method further comprises: receiving an indication of relative movement between the packet receiver and the packet transmitter (200b, 200c,..., 200N); and in response thereto: resetting the LPF to a default state, wherein in the default state the automatic gain control value does not depend on any previous automatic gain control value. receiving a packet from a packet transmitter (200b, 200c,..., 200N), wherein the packet comprises a preamble, wherein the preamble is composed of a single orthogonal frequency-division multiplexing, OFDM, symbol and represented by a sequence of samples; applying variable gain amplitude control to the sequence of samples, thereby resulting in a sequence of variable gain amplitude controlled samples; applying automatic gain control to the sequence of variable gain amplitude controlled samples to produce an automatic gain control value, wherein the automatic gain control involves applying (S106b) a low-pass filter, LPF, to the sequence of variable gain amplitude controlled samples, wherein the LPF is selected from a bank of LPFs, wherein which LPF to apply depends on, according to the time based scheduling, from which packet transmitter (200b, 200c,..., 200N) the packet is received; and feeding the automatic gain control value as a control signal to be used during the variable gain amplitude control when applied to a next packet from the same packet transmitter (200b, 200c,..., 200N), wherein the automatic gain control value depends, via the LPF, on a previous automatic gain control value for the same packet transmitter (200b, 200c,..., 200N), and wherein the method further comprises: receiving an indication of relative movement between the packet receiver and the packet transmitter (200b, 200c,..., 200N); and in response thereto: resetting the LPF to a default state, wherein in the default state the automatic gain control value does not depend on any previous automatic gain control value.