Abstract: A MIMO wireless system includes a transmitter that has a transmitter having a parser that parses a bit stream into multiple spatial data streams and multiple interleavers corresponding to the multiple spatial data streams, where each interleaver interleaves the bits in the corresponding spatial data stream by performing multiple column rotation to increase diversity of the wireless system. The MIMO wireless system also includes a receiver that has deinterleavers that deinterleaves spatial bit streams transmitted by the transmitter.

Abstract: Disclosed is a system and method for providing backward compatible transmitter diversity in an orthogonal frequency division modulated (OFDM) communication system. According to one aspect of the invention, a method for providing backward compatible transmitter diversity includes the steps of: receiving an input data bit stream; transforming it into an OFDM symbol stream comprised of even and odd symbols; dividing the OFDM symbol stream into a first symbol sub-stream and a second symbol sub-stream; processing the first symbol sub-stream by a first processing block to output a first processed symbol sub-stream; processing the second symbol sub-stream by a second processing block to output a second processed symbol sub-stream; transmitting the first processed symbol sub-stream from a first diversity antenna; and transmitting the second processed symbol sub-stream from a second diversity antenna and both are transmitted over non-overlapping frequencies.

Abstract: A system and method are provided for optimal decoding in a Coded Orthogonal Frequency Division Multiplexing diversity system. The system and method improve the performance of 802.11a receivers by combining optimal maximum likelihood decoding with symbol level decoding such that the performance advantages of optimal maximum likelihood decoding are provided with the same computational complexity as Alamouti symbol level decoding method.

Abstract: A method for a beam forming configuration is provided. A representation of a 3D polygon is formed from a plurality of blocks. The blocks are arranged according to a frequency, a time, and a space within the 3D polygon. Based on the frequency, the time, and the space of an electronic signal, one of the blocks is selected. An equation that is based on the block or to the block and the blocks relationship to one or more of the other blocks is used to form an output.

Abstract: Bit level, rather than symbol level, diversity combining is employed within a wireless communications receiver. Channel estimates and bit metrics are separately computed for signals received by different antenna elements. Bit metrics are calculated by determining a least squares cumulative difference between all bits within the received symbol and corresponding bits within constellation symbols as modified by the channel estimate. The separately-determined bit metrics are then combined for decoding. Performance improvements over both single antenna systems and multiple antenna systems with symbol level diversity combining are achieved.

Abstract: A method and system for combining signals in a receiver are provided. If the current packet is determined to be the retransmitted packet according to predetermined criteria, The retransmitted packet and the previously stored packet in error with the same packet number are combined using a maximum ratio combining method according to the signal-to-noise-ratio (SNR) calculated from the preamble of each packet. With this type of diversity combining, a reliable data packet transmission in a shorter time period can be obtained while increasing the SNR and reducing the throughput time in multipath channel.

Abstract: A timing recovery loop in the front end of a digital receiver includes a sample rate converter which receives a symbol stream at a first sampling rate and outputs the symbol stream at a second sampling rate responsive to a timing recovery (TR) control signal, a forward equalizer generating an equalized feedback signal based on the symbol stream at the second sampling rate, and a timing recovery circuit generating the TR control signal based upon the equalized feedback signal. If desired, the timing recovery loop may include a carrier recovery circuit electrically coupling the sample rate converter to the forward equalizer and a finite impulse response (FIR) filter electrically coupling the carrier recovery circuit to the forward equalizer. In an exemplary case, the FIR filter is a square-root raised cosine filter. A method for controlling the timing recovery loop based on the equalized feedback signal and a corresponding timing recovery control signal are also described.

Abstract: A magnitude only equalizer equalizes a magnitude of a received wireless signal without regard to phase distortions introduced, and transmits the magnitude equalized signal to a timing recovery loop for improved correlation peak detection in a sync based timing recovery scheme. A channel equalizer receiving the output signal from the timing recovery loop equalizes the signal and corrects any phase distortions introduced by the magnitude only equalizer. The magnitude only equalizer includes at least one filter utilizing only real coefficients and constrained such that the direct term of the overall filter structure within the magnitude only equalizer is unity.