RTL8188CUB8
Slim Module Combo Card User Manual
1
Rev.1.0
1. General Description
1.1. RTL8188CUB8
The Realtek RTL8188CU B8 is a highly integrated single-chip W ireless LAN (W LAN) controller
compatible with the IEEE 802.11n specification. It combines a MAC, a 1T1R capable baseband, and RF in
a single chip. The RTL8188CUB8 provides a complete solution for a high-performance wireless client.
The RTL8188CUB8 baseband implements Multiple Input, Multiple Output (MIMO) Orthogonal Frequency
Division Multiplexing (OFDM) with one transm it and one receive path (1T1R). Features include one
spatial stream transmission, short Guard Interval (GI) of 400ns, spatial spreading, and support for both
20MHz and 40MHz channel bandwidth.
For legacy compatibility, Direct Sequence Spread Spectrum (DSSS), Complementary Code Keying (CCK)
and OFDM baseband processing are included to support all IEEE 802.11b, and 802.11g data rates.
Differential phase shift keying modulation schemes, DBPSK and DQPSK with data scrambling capability
are available, and CCK provides support for legacy data rates, with long or short preamble. The high speed
FFT/IFFT paths, com bined with BPSK, QPSK, 16QAM, and 64QAM m odulation of the individual
subcarriers, and rate compatible punctured convolutional coding with coding rate of 1/2, 2/3, 3/4, and 5/6,
provide higher data rates of 54Mbps and 150Mbps for IEEE 802.11g and 802.11n OFDM respectively.
The RTL8188CUB8 builds in an enhanced signal detect or, an adaptive frequency dom ain equalizer, and a
soft-decision Viterbi decoder to alleviate severe multi-path effects and mutual interference in the reception
of multiple streams. Robust interference detecti on and suppression are provided to protect against
Bluetooth, cordless phone, and microwave oven interference.
Efficient IQ-imbalance, DC offset, phase noise, fre quency offset, and tim ing offset com pensations are
provided for the radio frequency front-end. Selectable digital transmit and receive FIR filters are provided
to meet transmit spectrum mask requirements and to reject adjacent channel interference, respectively.
The RTL8188CUB8 supports fast receiver Autom atic Gain Control (AGC) with synchronous and
asynchronous control loops am ong antennas, antenna diversity functions, and adaptive transm it power
control functions to obtain better performance in the analog portions of the transceiver.
The RTL8188CUB8 MAC supports 802.11e for multimedia applications, 802.11i for security, and 802.11n
for enhanced MAC protocol efficiency. Using packet aggregation techniques such as A-MPDU with BA
and A-MSDU, protocol efficiency is significantly improved. Power saving mechanisms such as U-APSD,
and APSD, reduces power wasted during idle tim e, and compensates for the extra power required to
transmit OFDM. The RTL8188CUB8 provides simple legacy and 20MHz/40MHz co-existence mechanisms
to ensure backward and network compatibility.
