RTL8192EEBT
user manual
4
1.
General Description
The Realtek RTL8192EE is a highly integrated single-chip MIMO (Multiple In, Multiple Out) Wireless LAN
(WLAN) solution for the wireless high throughput 802.11n specification. It combines a MAC, a 2T2R capable
baseband, and RF in a single chip. The RTL8192EE provides a complete solution for a high throughput
performance wireless client.
The RTL8192EE baseband implements Multiple Input, Multiple Output (MIMO) Orthogonal Frequency
Division Multiplexing (OFDM) with 2 transmit and 2 receive paths (2T2R) and is compatible with the IEEE
802.11n specification. Features include two spatial streams transmission, short Guard Interval (GI) of 400ns,
spatial spreading, and transmission over 20MHz and 40MHz bandwidth. The RTL8192EE provides a spatial
stream Space-Time Block Code (STBC) and Low Density Parity Check (LDPC) encoding and decoding to
extend the range of transmission. At the receiver, extended range and good minimum sensitivity is achieved by
having receiver diversity up to two antennas. As the recipient, the RTL8192EE also supports explicit sounding
packet feedback that helps senders with beamforming capability. With two independent RF blocks, the
RTL8192EE can perform fast roaming without link interruption.
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
along with complementary code keying to provide data rates of 1, 2, 5.5 and 11Mbps with long or short
preamble. The high-speed FFT/IFFT paths, combined with BPSK, QPSK, 16QAM, and 64QAM modulation
of the individual subcarriers and rate compatible punctured convolutional coding with coding rate of 1/2, 2/3,
3/4, and 5/6, provides the maximum data rate of 54Mbps and 300Mbps for IEEE 802.11g and 802.11n MIMO
OFDM respectively.
The RTL8192EE builds in an enhanced signal detector, an adaptive frequency domain equalizer, and a
soft-decision Viterbi decoder to alleviate severe multi-path effects and mutual interference in the reception of
multiple streams. For better detection quality, receive diversity with maximal-ratio-combine (MRC) applying
up to 2 receive paths are implemented. Robust interference detection and suppression are provided to protect
against Bluetooth, cordless phone, and microwave oven interference. Receive vector diversity for multi-stream
application is implemented for efficient utilization of MIMO channels. Efficient IQ-imbalance, DC offset,
phase noise, frequency offset, and timing offset compensations are provided for radio frequency front-end
impairments. Selectable digital transmit and receive FIR filters are provided to meet transmit spectrum mask
requirements and to reject adjacent channel interference, respectively.
The RTL8192EE supports fast receiver Automatic Gain Control (AGC) with synchronous and asynchronous
control loops among antennas, antenna diversity functions, and adaptive transmit power control functions to
obtain the better performance in the analog portions of the transceiver.
The RTL8192EE 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 Legacy Power Save,
U-APSD, and MIMO power saving reduce the power wasted during idle time, and compensate for the extra
power required to transmit MIMO OFDM. The RTL8192EE provides simple legacy and 20MHz/40MHz
co-existence mechanisms to ensure backward and network compatibility.