Realtek RTL8191SE - Verkkosovitin - PCIe Half Mini Card - 802.11b/g/n

The Realtek RTL8191SE 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 1T2R capable baseband, and RF in a single chip. The RTL8191SE provides a complete solution for a high throughput performance wireless client.

The RTL8191SE baseband implements Multiple Input, Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) with 1 transmit and 2 receive paths and is compatible with the IEEE 802.11n specification. Features include one spatial stream transmission, up to two spatial streams reception, short guard interval (GI) of 400ns, spatial spreading, and transmission over 20 MHz and 40 MHz bandwidth. At the receiver, extended range and good minimum sensitivity is achieved by having receiver diversity up to 2 antennas.

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 the data rates of 1, 2, 5.5 and 11 Mbps 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 54 Mbps and 300 Mbps for IEEE 802.11g and 802.11n MIMO OFDM respectively.

The RTL8191SE builds in an enhanced signal detector, an adaptive frequency domain equalizer, and a soft-decision Viterbi decoder to alleviate the 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 the radio frequency front-end impairments. Selectable digital transmit and receiver FIR filters are provided to meet transmit spectrum mask requirements and to reject adjacent channel interference, respectively.

The RTL8191SE supports fast receiver automatic gain control (AGC) with synchronous and asynchronous control loops among antennas, antenna diversity functions, and adaptive transmit power control function to obtain the better performance in the analog portions of the transceiver.

The RTL8191SE 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 RTL8191SE provides simple legacy and 20 MHz/40 MHz co-existence mechanisms to ensure backward and network compatibility.