由于某种我不知道的原因，我的 wifi 信号在 Linux 中非常弱，但在 Windows 中却没问题。速度似乎不是问题，但与 wifi 信号本身的强度有关。我使用的是 ASUS N580VD-DM129T，在带有 Gnome 的 Linux Ubuntu 16.04 中，我拥有适用于 Intel(R) 双频无线 AC 8265 的 iwlwifi 驱动程序。（我检查了使用的网卡名称，dmesg | grep iwlwifi并查找了输出行“检测到 Intel(R) 双频无线 AC 8265，REV=0x230”）。我也尝试运行 Ubuntu 18.04，但仍然遇到同样的问题。
我运行时的输出dmesg | grep iwlwifi如下：
[ 3.347436] iwlwifi 0000:03:00.0: enabling device (0000 -> 0002)
[ 3.386096] iwlwifi 0000:03:00.0: Direct firmware load for iwlwifi-8265-33.ucode failed with error -2
[ 3.388185] iwlwifi 0000:03:00.0: Direct firmware load for iwlwifi-8265-32.ucode failed with error -2
[ 3.397339] iwlwifi 0000:03:00.0: loaded firmware version 31.560484.0 op_mode iwlmvm
[ 3.412232] iwlwifi 0000:03:00.0: Detected Intel(R) Dual Band Wireless AC 8265, REV=0x230
[ 3.472665] iwlwifi 0000:03:00.0: base HW address: 88:b1:11:5e:93:f4
[ 3.550283] iwlwifi 0000:03:00.0 wlp3s0: renamed from wlan0
我觉得加载失败两次才成功很奇怪，想知道这是否是问题所在，但事实并非如此。我安装了 iwlwifi-8265-ucode-22.361476.0.tgz，可在https://wireless.wiki.kernel.org/en/users/Drivers/iwlwifi并且失败了很多次 (33、32、31，直到 23，然后使用版本 22)。所以它只是在搜索可用的版本。
我还尝试按照建议更改 iwlwifi 模块中的某些选项这里。但是它不起作用。更准确地说，我options iwlwifi 11n_disable=1 swcrypto=1在文件 /etc/modprobe.d/iwlwifi.conf 的末尾添加了以下内容：
remove iwlwifi \
(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
&& /sbin/modprobe -r mac80211
options iwlwifi 11n_disable=1 swcrypto=1
$sudo modprobe -rv iwlwifi甚至当我运行删除模块然后$sudo modprobe -v iwlwifi再次添加它时这也不起作用。
编辑2：我也尝试了 Linux 17.10 和 18.04，但仍然遇到同样的问题（与 Windows 相比信号较弱）。
编辑3：尝试针对 realtek 的建议也不起作用：
sudo modprobe -v iwlwifi ant_sel=2
https://connectwww.com/how-to-solve-realtek-rtl8723be-weak-wifi-signal-problem-in-ubuntu/4625/
编辑5：尝试改变电源管理运行
sudo sed -i 's/wifi.powersave = 3/wifi.powersave = 2/' /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf
然后systemctl restart network-manager.service也没用。这是建议这里和这里。此链接解释如何做。
编辑4：当我运行时，$ nmcli dev wifi list我得到以下结果：
* SSID MODE CHAN RATE SIGNAL BARS SECURITY
neuromancer Infra 11 54 Mbit/s 59 ▂▄▆_ WPA2
* waffles Infra 11 54 Mbit/s 48 ▂▄__ WPA2
Stephens_iMac Infra 11 54 Mbit/s 47 ▂▄__ WPA2
eduroam Infra 11 54 Mbit/s 45 ▂▄__ WPA2 802.1X
mac-sfg003 Infra 11 54 Mbit/s 42 ▂▄__
Crumpet Infra 11 54 Mbit/s 37 ▂▄__
Neuromancer 实际上距离我只有 2.5 米，而且还没有完全恢复。（请注意，编辑 4 和编辑 1 是在不同的日期运行的，因此发现的网络不同）
编辑1：运行后$ sudo iwlist scan输出以下结果
lo Interface doesn't support scanning.
enp4s0 Interface doesn't support scanning.
wlp3s0 Scan completed :
Cell 01 - Address: 58:97:1E:72:D0:A1
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=46/70 Signal level=-64 dBm
Encryption key:on
ESSID:"eduroam"
Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s
54 Mb/s
Mode:Master
Extra:tsf=00000078646f81d9
Extra: Last beacon: 4328ms ago
IE: Unknown: 0007656475726F616D
IE: Unknown: 01061824B048606C
IE: Unknown: 030101
IE: Unknown: 050700010900200000
IE: Unknown: 0706474220010D14
IE: Unknown: 0B051B006F093D
IE: Unknown: 200100
IE: Unknown: 2A0100
IE: Unknown: 2D1A2C181BFFFF000000000000000000000000000000000000000000
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : CCMP
Pairwise Ciphers (1) : CCMP
Authentication Suites (1) : 802.1x
IE: Unknown: 3603E21600
IE: Unknown: 3D1601000700000000000000000000000000000000000000
IE: Unknown: 460573C0000000
IE: Unknown: 7F06001000000140
IE: Unknown: 851E27008F000F00FF035900636E63622D6C61625F617265615F6C001B000036
IE: Unknown: 9606004096001100
IE: Unknown: DD180050F2020101800003A44F0027A44F004243800072324100
IE: Unknown: DD06004096010104
IE: Unknown: DD050040960305
IE: Unknown: DD050040960B69
IE: Unknown: DD050040961409
IE: Unknown: DD16000B85F800015AA6AA0DD0F287C653371F84DC6C1608
Cell 02 - Address: 58:97:1E:72:D0:A0
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=47/70 Signal level=-63 dBm
Encryption key:off
ESSID:"OWL"
Bit Rates:12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s; 48 Mb/s
54 Mb/s
Mode:Master
Extra:tsf=0000007864711990
Extra: Last beacon: 4272ms ago
IE: Unknown: 00034F574C
IE: Unknown: 01061824B048606C
IE: Unknown: 030101
IE: Unknown: 050F000108002000000000000000010000
IE: Unknown: 0706474220010D14
IE: Unknown: 0B051B006F093D
IE: Unknown: 2A0100
IE: Unknown: 2D1A2C181BFFFF000000000000000000000000000000000000000000
IE: Unknown: 3D1601000700000000000000000000000000000000000000
IE: Unknown: 7F06001000000140
IE: Unknown: 851E27008F000F00FF035900636E63622D6C61625F617265615F6C001B000036
IE: Unknown: 9606004096001100
IE: Unknown: DD180050F2020101800003A44F0027A44F004243800072324100
IE: Unknown: DD06004096010104
IE: Unknown: DD050040960305
IE: Unknown: DD050040960B09
IE: Unknown: DD050040961408
IE: Unknown: DD16000B85F800015AA6AA0D68445B38B7430C870C13ED10
Cell 03 - Address: 28:F0:76:49:02:32
Channel:11
Frequency:2.462 GHz (Channel 11)
Quality=40/70 Signal level=-70 dBm
Encryption key:on
ESSID:"Stephens_iMac"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
24 Mb/s; 36 Mb/s; 54 Mb/s
Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
Mode:Master
Extra:tsf=0000073adbc53791
Extra: Last beacon: 3732ms ago
IE: Unknown: 000D5374657068656E735F694D6163
IE: Unknown: 010882848B962430486C
IE: Unknown: 03010B
IE: Unknown: 2A0100
IE: Unknown: 32040C121860
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : CCMP
Pairwise Ciphers (1) : CCMP
Authentication Suites (1) : PSK
IE: Unknown: 2D1AAD4917FFFFFF0000000000000000000000000000000000000000
IE: Unknown: 3D160B000400000000000000000000000000000000000000
IE: Unknown: 7F080400000000000040
IE: Unknown: DD150017F209000108694D616331372C31010103010000
IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00
Cell 04 - Address: 58:97:1E:72:D0:AE
Channel:100
Frequency:5.5 GHz (Channel 100)
Quality=32/70 Signal level=-78 dBm
Encryption key:on
ESSID:"eduroam"
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=00000352afa2581c
Extra: Last beacon: 2160ms ago
IE: Unknown: 0007656475726F616D
IE: Unknown: 0104B048606C
IE: Unknown: 050400010100
IE: Unknown: 070C47422024081764051784031E
IE: Unknown: 0B05010006093D
IE: Unknown: 200100
IE: Unknown: 2D1A6E181BFFFF000000000000000000000000000000000000000000
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : CCMP
Pairwise Ciphers (1) : CCMP
Authentication Suites (1) : 802.1x
IE: Unknown: 3603E21600
IE: Unknown: 3D1664050400000000000000000000000000000000000000
IE: Unknown: 460573C0000000
IE: Unknown: 7F06001000000140
IE: Unknown: 851E03008F000F00FF035900636E63622D6C61625F617265615F6C0001000035
IE: Unknown: 9606004096001100
IE: Unknown: DD180050F2020101800003A44F0027A44F004243800072324100
IE: Unknown: DD06004096010104
IE: Unknown: DD050040960305
IE: Unknown: DD050040960B69
IE: Unknown: DD050040961409
IE: Unknown: DD16000B85F800015AA6AA0F1A1ABC93574E004A621EB445