Low complexity maximum likelihood detection of concatenate space codes for wireless applications
AssigneeAT&T Wireless Services, Inc.
InventorsSiavash Alamouti, Patrick Poon, Vahid Tarokh
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Abstract
Good transmission characteristics are achieved in the presence of fading with a transmitter that employs a trellis coder followed by a block coder. Correspondingly, the receiver comprises a Viterbi decoder followed by a block decoder. Advantageously, the block coder and decoder employ time-space diversity coding which, illustratively, employs two transmitter antennas and one receiver antenna.
Claims19
In a data communication system employing space diversity via two or more transmitting antennas, a receiver comprising:
- a space block combiner configured for receiving data transmitted from the two or more transmitting antennas, and
- a Viterbi decoder responsive to output signals of the space block combiner.
In a receiver, a method for linking trellis codes with block codes, the method comprising:
- receiving on a single receiver antenna, a first baseband signal and a second baseband signal, wherein the first and second baseband signals were transmitted using space-time coding;
- determining channel estimates for the received first and second baseband signals;
- using the determined channel estimates, generating a first combined signal based on the first received baseband signal and a second combined signal based on the second received signal, the first and second combined signals including a complex multiplicative distortion factor;
- and
- based on the first generated combined signal, building a first metric corresponding to a first hypothesized symbol, the first hypothesized symbol replicating the received first baseband signal prior to transmission;
- and
- based on the second generated combined signal, building a second metric corresponding to a second hypothesized symbol, the second hypothesized symbol replicating the received second baseband signal prior to transmission.
In a receiver, an apparatus for linking trellis codes with block codes, the apparatus comprising:
- means for receiving on a single receiver antenna, a first baseband signal and a second baseband signal, wherein the received first and second baseband signals were encoded at a transmitter having at least two transmit antennas coupled to an at least two branch trellis encoder;
- means, coupled to the means for receiving, for determining channel estimates for the received first and second baseband signals;
- means, coupled to the means for determining, for using the determined channel estimates and generating a first combined block signal based on the first received baseband signal and a second combined block signal based on the second received signal, wherein the first and second combined signals include a complex multiplicative distortion factor;
- and
- means for building a combined metric for a hypothesized branch symbol, the hypothesized symbol replicating both the received first and second symbols.
Dependencies are inferred from the claim text.