Qualcomm Incorporated

University of California

Anand D Subramaniam

Tamer Adel Kadous

Ashok Mantravadi

Gordon Kent Walker

Fuyun Ling

Rajiv Vijayan

Krishnamurthy Viswanathan, Legal Representative

Dhananjay Ashok Gore

Ranganathan Krishnan

Bhaskar Dharanipragada Rao

Murali Chari

Seyfullah Halit Oguz

Ramaswamy Murali

Ramaaswamy Murali

Accordingly, a method and apparatus are provided to convert received content into a first stream and a second stream, to transmit said first stream using a first tone and to transmit said second stream using an orthogonal scheme. A layering scheme is used to transmit the base stream covering a smaller area and an enhanced stream is used to cover a large utilizing orthogonal scheme.

Method for transmitting multiple streams in wireless broadcast networks

To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

Local and wide-area transmissions in a wireless broadcast network

Techniques are provided to support successive interference cancellation (SIC) receiver processing with selection diversity whereby each of Ntransmit antennas may be turned on or off. One symbol stream may be transmitted from each transmit antenna. A SIC receiver recovers the transmitted symbol streams in a specific order. Up to N! orderings are evaluated. For each ordering, Npost-detection SNRs are obtained for Ntransmit antennas and used to determine Ndata rates, where the data rate is zero if the post-detection SNR is worse than a minimum required SNR. An overall data rate is computed for each ordering based on the Ndata rates. The ordering with the highest overall data rate is selected for use. Up to Nsymbol streams are processed at the data rates for the selected ordering and transmitted. The transmitted symbol streams are recovered in accordance with the selected ordering.

Successive interference cancellation receiver processing with selection diversity

Pilot and data transmission schemes for multi-antenna communication systems utilizing multi-carrier modulation are provided. Subband multiplexing is used to avoid interference resulting from transmitting multiple signals simultaneously from multiple antennas. M usable subbands are initially arranged to form multiple groups of subbands, with each group including a different subset of the usable subbands. Each of T transmit antennas is then assigned one or possibly more subband groups for pilot transmission and typically one subband group for data transmission. Pilot and data may then be transmitted from each antenna on the subbands assigned to that antenna for pilot and data transmission. For each transmit antenna, the transmit power for each assigned subband may be scaled higher such that all of the total transmit power available for the antenna is used for transmission. Pilot and/or data may be transmitted simultaneously from all T antennas on all usable subbands without causing mutual interference.

Transmission schemes for multi-antenna communication systems utilizing multi-carrier modulation

Techniques to derive a channel estimate using substantially fewer number of complex multiplications than with a brute-force method to derive the same channel estimate. In one method, an intermediate vector B is initially derived based on K sub-vectors of a vector &#x124; for a channel frequency response estimate and at least two DFT sub-matrices for a DFT matrix {tilde over (W)}, where K&#x3e;1. An intermediate matrix A for the DFT matrix {tilde over (W)} is also obtained. A least square channel impulse response estimate is then derived based on the intermediate vector B and the intermediate matrix A. In one implementation, the intermediate vector B is obtained by first computing DFTs of a matrix &#x124;, which is formed based on the vector &#x124;, to provide a matrix G. Inner products between the columns of a base DFT sub-matrix Wand the rows of the matrix Gare then computed to obtain the entries of the intermediate vector B.

Reduced complexity channel estimation for wireless communication systems

According to the invention, quantization encoding is conducted using the probability density function of the source, enabling fixed, variable and adaptive rate encoding. To achieve adaptive encoding, an update is conducted with a new observation of the data source, preferably with each new observation of the data source. The current probability density function of the source is then estimated to produce codepoints to vector quantize the observation of the data source.

Fixed, variable and adaptive bit rate data source encoding (compression) method

According to the invention, quantization encoding is conducted using the probability density function of the source, enabling fixed, variable and adaptive rate encoding. To achieve adaptive encoding, an update is conducted with a new observation of the data source, preferably with each new observation of the data source, preferably with each new observation of the data source. The current probability density function of the source is then estimated to produce codepoints to vector quantize the observation of the data source.

Techniques to derive a channel estimate using substantially fewer number of complex multiplications than with a brute-force method to derive the same channel estimate. In one method, an intermediate vectoris initially derived based on K sub-vectors of a vector {circumflex over ()} for a channel frequency response estimate and at least two DFT sub-matrices for a DFT matrix {tilde over ()}, where K&#x3e;1. An intermediate matrixfor the DFT matrix {tilde over ()} is also obtained. A least square channel impulse response estimate is then derived based on the intermediate vectorand the intermediate matrix. In one implementation, the intermediate vectoris obtained by first computing DFTs of a matrix, which is formed based on the vector {circumflex over ()}, to provide a matrix. Inner products between the columns of a base DFT sub-matrixand the rows of the matrixare then computed to obtain the entries of the intermediate vector.

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San Diego, CA, United States of America

Anand D Subramaniam