A method comprising: (i) receiving a high efficiency frame in a wireless communication network of an IEEE 802.11ax and/or IEEE 802.11ah standard by a wireless device (301, 311), wherein the HE frame comprises a legacy preamble containing a first training field (112; L-LTF) and a high efficiency preamble containing a signal field (RL-SIG, HE-SIGA1, HE-SIGA2; 114, 115, 116) and a second training field (118; HE-LTF); (ii) performing first channel estimation based on a legacy long training field (112; L-LTF) as the first training field for a first channel condition and providing a first channel response matrix (H L-LTF); (iii) performing a second channel estimation based on a HE long training field (118; HE-LTFS) for data as the second training field for a second channel condition and providing a second channel response matrix (H HE-LTF); (iv) decoding a beam-change indicator based on a HE signal A field (HE-SIGT-A) and based on the first channel response matrix (H L-LTF) thereby providing said indicator and determining whether there is beam change between a first channel condition and a second channel condition; (v) performing AGC updating based on the indicator and a HE short training field (117; HE-STF) for data as a signal field and providing an output; (vi) performing a re-modulation for channel estimation enhancement based (a) on a legacy signal field (113; L-SIG) contained in the legacy preamble, (b) on an HE signal field (115, 116; HE-SIG-A) and on a repeat legacy signal field (114, RL-SIG) both contained in the high-efficiency preamble as signal fields, and (c) the output of the AGC updating and (d) providing re-modulated signal fields (RM-SIG) as symbols; and (vii) performing channel estimation enhancement based (a) on both the first training field (112; L-LTF) and the second training field (118; HE-LTFS) if the beam-change indicator indicates no beam change, (b) on said indicator, (c) said re-modulated signal fields (RM-SIG), and (d) said second channel response matrix (H HE-LTF) and providing an enhanced channel response matrix (H C) as said improvement of performance. (i) receiving a high efficiency frame in a wireless communication network of an IEEE 802.11ax and/or IEEE 802.11ah standard by a wireless device (301, 311), wherein the HE frame comprises a legacy preamble containing a first training field (112; L-LTF) and a high efficiency preamble containing a signal field (RL-SIG, HE-SIGA1, HE-SIGA2; 114, 115, 116) and a second training field (118; HE-LTF); (ii) performing first channel estimation based on a legacy long training field (112; L-LTF) as the first training field for a first channel condition and providing a first channel response matrix (H L-LTF); (iii) performing a second channel estimation based on a HE long training field (118; HE-LTFS) for data as the second training field for a second channel condition and providing a second channel response matrix (H HE-LTF); (iv) decoding a beam-change indicator based on a HE signal A field (HE-SIGT-A) and based on the first channel response matrix (H L-LTF) thereby providing said indicator and determining whether there is beam change between a first channel condition and a second channel condition; (v) performing AGC updating based on the indicator and a HE short training field (117; HE-STF) for data as a signal field and providing an output; (vi) performing a re-modulation for channel estimation enhancement based (a) on a legacy signal field (113; L-SIG) contained in the legacy preamble, (b) on an HE signal field (115, 116; HE-SIG-A) and on a repeat legacy signal field (114, RL-SIG) both contained in the high-efficiency preamble as signal fields, and (c) the output of the AGC updating and (d) providing re-modulated signal fields (RM-SIG) as symbols; and (vii) performing channel estimation enhancement based (a) on both the first training field (112; L-LTF) and the second training field (118; HE-LTFS) if the beam-change indicator indicates no beam change, (b) on said indicator, (c) said re-modulated signal fields (RM-SIG), and (d) said second channel response matrix (H HE-LTF) and providing an enhanced channel response matrix (H C) as said improvement of performance.