Broadcom BCM4313 802.11bgn 无线网络适配器 [14e4:4727] (rev 01) 不适用于 Ubuntu 18.04

lspci -vvnn | grep -A 9 Network 

08:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM4313 802.11bgn Wireless Network Adapter [14e4:4727] (rev 01)
    Subsystem: Broadcom Inc. and subsidiaries BCM4313 802.11bgn Wireless Network Adapter [14e4:051b]
    Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
    Latency: 0, Cache Line Size: 64 bytes
    Interrupt: pin A routed to IRQ 17
    Region 0: Memory at e0400000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>
    Kernel driver in use: wl
    Kernel modules: bcma, wl

iwconfig

lo        no wireless extensions.

enp7s0    no wireless extensions.

wlp8s0    IEEE 802.11  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off

我尝试了几乎所有我看到的关于它的东西，但它仍然是一样的。我正在使用联想 G570。帮我。而且我在这里尝试了安装 Broadcom 驱动程序中的大部分内容，但仍然没有 wifi。

rfkill list all

0: ideapad_wlan: Wireless LAN
    Soft blocked: no
    Hard blocked: yes
1: ideapad_bluetooth: Bluetooth
    Soft blocked: no
    Hard blocked: yes
2: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no
3: brcmwl-0: Wireless LAN
    Soft blocked: no
    Hard blocked: yes