[ubuntu] Slow WiFi in hp CQ45-118 using 14.04 LTS broadcom

Hello Ubuntu comunity

I've been trying different possible solutions to repair the wifi in my laptop, in fact using the same machine loading windows arrives
at having the max of the inteet coection at my home which is 20MB but with Ubuntu is around 4 to 7 Mb, any suggestion would be
fully appreciated, thank you very much in advance for your time

lspci -
sudo lshw -C network

00:00.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] RS780 Host Bridge [1022:9600]
00:01.0 PCI bridge [0604]: Hewlett-Packard Company Device [103c:9602]
00:04.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] RS780/RS880 PCI to PCI bridge (PCIE port 0) [1022:9604]
00:05.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] RS780/RS880 PCI to PCI bridge (PCIE port 1) [1022:9605]
00:06.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] RS780 PCI to PCI bridge (PCIE port 2) [1022:9606]
00:07.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] RS780/RS880 PCI to PCI bridge (PCIE port 3) [1022:9607]
00:11.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode] [1002:4391]
00:12.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller [1002:4397]
00:12.1 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0 USB OHCI1 Controller [1002:4398]
00:12.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller [1002:4396]
00:13.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller [1002:4397]
00:13.1 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0 USB OHCI1 Controller [1002:4398]
00:13.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller [1002:4396]
00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller [1002:4385] (rev 3a)
00:14.1 IDE interface [0101]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 IDE Controller [1002:439c]
00:14.2 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA) [1002:4383]
00:14.3 ISA bridge [0601]: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller [1002:439d]
00:14.4 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 PCI to PCI Bridge [1002:4384]
00:18.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 11h Processor HyperTransport Configuration [1022:1300] (rev 40)
00:18.1 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 11h Processor Address Map [1022:1301]
00:18.2 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 11h Processor DRAM Controller [1022:1302]
00:18.3 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 11h Processor Miscellaneous Control [1022:1303]
00:18.4 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Family 11h Processor Link Control [1022:1304]
01:05.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] RS780M [Mobility Radeon HD 3200] [1002:9612]
01:05.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] RS780 HDMI Audio [Radeon (HD) 3000 Series] [1002:960f]
08:00.0 System peripheral [0880]: JMicron Technology Corp. SD/MMC Host Controller [197b:2382]
08:00.2 SD Host controller [0805]: JMicron Technology Corp. Standard SD Host Controller [197b:2381]
08:00.3 System peripheral [0880]: JMicron Technology Corp. MS Host Controller [197b:2383]
08:00.4 System peripheral [0880]: JMicron Technology Corp. xD Host Controller [197b:2384]
09:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g LP-PHY [14e4:4315] (rev 01)
0a:00.0 Etheet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Etheet controller [10ec:8136] (rev 02)

PCI (sysfs)
*-network
description: Network controller
product: BCM4312 802.11b/g LP-PHY
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:09:00.0
version: 01
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list
configuration: driver=b43-pci-bridge latency=0
resources: irq:18 memory:d1100000-d1103fff
*-network
description: Etheet interface
product: RTL8101/2/6E PCI Express Fast/Gigabit Etheet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:0a:00.0
logical name: eth1
version: 02
serial: 00:1e:ec:aa:0c:fe
size: 10Mbit/s
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list rom etheet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s
resources: irq:44 ioport:2000(size=256) memory:d1010000-d1010fff memory:d1000000-d100ffff memory:d1020000-d103ffff
*-network
description: Wireless interface
physical id: 1
logical name: wlan3
serial: 00:21:00:68:66:c7
capabilities: etheet physical wireless
configuration: broadcast=yes driver=b43 driverversion=3.13.0-85-generic firmware=666.2 ip=192.168.2.12 link=yes multicast=yes wireless=IEEE 802.11bg