Multiple streams using partial stbc with sdm within a wireless local area network

This application claims priority of U.S. Provisional Patent Application Ser. No. 60/604,050, filed Aug. 25, 2004. The subject matter of this earlier filed application is hereby incorporated by reference.

1. Technical Field of the Invention

This invention relates generally to wireless communication systems and more particularly to a transmitter transmitting at high data rates with such wireless communication systems. Additionally, the present invention allows the detection and reception of multiple data streams for higher data rates.

2. Description of Related Art

Communication systems support wireless and wire lined communications between wireless and/or wire lined communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11, BLUETOOTH™, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof.

For each wireless communication device to participate in wireless communications, it may include a built-in radio transceiver (i.e., receiver and transmitter) or may be coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.). The transmitter may include a data modulation stage, one or more intermediate frequency stages, and a power amplifier. The data modulation stage converts raw data into baseband signals in accordance with a particular wireless communication standard. The one or more intermediate frequency stages mix the baseband signals with one or more local oscillations to produce RF signals. The power amplifier amplifies the RF signals prior to transmission via an antenna.

The transmitter may include a data modulation stage, one or more intermediate frequency stages, and a power amplifier. The data modulation stage can convert raw data into baseband signals in accordance with a particular wireless communication standard. The one or more intermediate frequency stages mix the baseband signals with one or more local oscillations to produce RF signals. The power amplifier amplifies the RF signals prior to transmission via an antenna.

The transmitter includes at least one antenna for transmitting the RF signals, which are received by a single antenna, or multiple antennas, of a receiver. When the receiver includes two or more antennas, the receiver will select one of them to receive the incoming RF signals. In this instance, the wireless communication between the transmitter and receiver is a single-output-single-input (SOSI) communication, even if the receiver includes multiple antennas that are used as diversity antennas (i.e., selecting one of them to receive the incoming RF signals). For SISO wireless communications, a transceiver includes one transmitter and one receiver.

Other types of wireless communications include single-input-multiple-output (SIMO), multiple-input-single-output (MISO), and multiple-input-multiple-output (MIMO). In a SIMO wireless communication, a single transmitter processes data into radio frequency signals that are transmitted to a receiver. The receiver includes two or more antennas and two or more receiver paths. Each of the antennas receives the RF signals and provides them to a corresponding receiver path (e.g., LNA, down conversion module, filters, and ADCs). Each of the receiver paths processes the received RF signals to produce digital signals, which are combined and then processed to recapture the transmitted data.

For a multiple-input-single-output (MISO) wireless communication, the transmitter includes two or more transmission paths (e.g., digital to analog converter, filters, up-conversion module, and a power amplifier) that each converts a corresponding portion of baseband signals into RF signals, which are transmitted via corresponding antennas to a receiver. The receiver includes a single receiver path that receives the multiple RF signals from the transmitter. In this instance, the receiver uses beam forming to combine the multiple RF signals into one signal for processing.

For a multiple-input-multiple-output (MIMO) wireless communication, the transmitter and receiver each include multiple paths. In such a communication, the transmitter parallel processes data using a spatial and time encoding function to produce two or more streams of data. The transmitter includes multiple transmission paths to convert each stream of data into multiple RF signals. The receiver receives the multiple RF signals via multiple receiver paths that recapture the streams of data utilizing a spatial and time decoding function. The recaptured streams of data are combined and subsequently processed to recover the original data.

With the various types of wireless communications (e.g., SISO, MISO, SIMO, and MIMO), providing a diversity of transmitted signals is important to ensure proper data integrity. However, prior art systems do not have the ability to separate and detect signals from multiple streams and realize the full benefits of those multiple streams. Therefore, a need exists for a receiver that has the ability to detect and separate signals from multiple streams so that coding and diversity gain may be realized.

According to one embodiment of the present invention, a method of communicating data to M receiving antennas from N transmitting antennas, where M and N are integers, the method includes the steps of receiving M data signals from M receive antennas, applying the M data signals to a space/time decoder to produce M decoded streams and reconstructing original data transmitted via N transmit antennas from the M decoded streams. At least P transmitting antennas transmit space-time block-coded signals and (N-P) transmitting antennas transmit code signals through spatial division multiplexing, where P is an integer.

Additionally, the step of reconstructing original data may include determining a number of transmit streams and configurations of those transmit streams through analysis of the M decoded streams. Also, P may be two and the step of receiving M data signals includes receiving two space-time block-coded signals. Also, when N is three, the step of receiving M data signals includes receiving a repetition code signal. Additionally, the step of reconstructing original data may include zero-forcing terms equivalent to relationships between signals sent from the N transmitting antennas to the M receiving antennas to cancel interference.

According to another embodiment, a receiver for communicating data from N transmitting antennas to M receiving antennas, where M and N are integers, includes receiving means for receiving M data signals via M receive antennas, applying means for applying the M data signals to a space/time decoder to produce M decoded streams and reconstructing means for reconstructing original data transmitted via N transmit antennas from the M decoded streams. At least P transmitting antennas transmit space-time block-coded signals and (N-P) transmitting antennas transmit code signals through spatial division multiplexing, where P is an integer.

According to another embodiment, a receiver for communicating data from N transmitting antennas to M receiving antennas, where M and N are integers includes M receive antennas, for receiving M data signals, a space/time decoder, configured to produce M decoded streams based on the M data signals and symbol demapping modules, configured to reconstruct original data transmitted via N transmit antennas from the M decoded streams. At least P transmitting antennas transmit space-time block-coded signals and (N-P) transmitting antennas transmit code signals through spatial division multiplexing, where P is an integer.