Wireless too slow in Ubuntu 18.4 Inspiron desktop

I am working on Dell Inspiron desktop with Ubuntu Linux 18.04. The wireless speed is too slow in my desktop. Following are the details:

description: Wireless interface
       product: QCA9565 / AR9565 Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlp3s0
       version: 01
       serial: 9c:30:5b:e6:d8:71
       width: 64 bits
       clock: 33MHz

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 005: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 004: ID 413c:2113 Dell Computer Corp. 
Bus 001 Device 003: ID 413c:301a Dell Computer Corp. 
Bus 001 Device 006: ID 0cf3:e005 Atheros Communications, Inc. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub