Teratech Corporation

Massachusetts Institute of Technology

Scott R Velazquez

Steven R Broadstone

Alice M Chiang

Truong O Nguyen

A wireless communication system employs directive antenna arrays and knowledge of position of users to form narrow antenna beams to and from desired users and away from undesired users to reduce co-channel interference. By reducing co-channel interference coming from different directions, spatial filtering with antenna arrays improves the call capacity of the system. A space division multiple access (SDMA) system allocates a narrow antenna beam pattern to each user in the system so that each user has its own communication channel free from co-channel interference. The position of the users is determined using geo-location techniques. Geo-location can be derived via triangulation between cellular base stations or via a global positioning system (GPS) receiver. The system can be optimized by applying partially adaptive processing algorithms, which are seeded by geo-location data.

Communication system using geographic position data

A wireless communication system employs directive antenna arrays and knowledge of position of users to form narrow antenna beams to and from desired users and away from undesired users to reduce co-channel interference. By reducing co-channel interference coming from different directions, spatial filtering with antenna arrays improves the call capacity of the system. A space division multiple access (SDMA) system allocates a narrow antenna beam pattern to each user in the system so that each user has its own communication channel free from co-channel interference. The position of the users is determined using geo-location techniques. Geo-location can be derived via triangulation between cellular base stations or via a global positioning system (GPS) receiver.

A hybrid filter bank analog-to-digital converter includes continuous-time analysis filters and discrete-time synthesis filters. The continuous-time analysis filters partition a continuous-time wideband input signal into continuous-time subband signals. An analog-to-digital converter bank quantizes the subband signals at a low data rate. A bank of upsamplers increases the data rate of the quantized subband signals. A bank of discrete-time synthesis filters processes the upsampled subband signals, generating signals which are the discrete-time approximation of the continuous-time subband signals. The subband signals may be recombined into a discrete-time wideband signal which is the discrete-time approximation of the continuous-time wideband input signal. The linearity errors, analog-to-digital converter mismatches and quantization noise are not compounded between the frequency bands, thereby increasing resolution. The system may also include compensators for compensating for non-linear behavior in the analog-to-digital converters and may include application-specific processors for further processing of the compensated subband signals. An alternative embodiment employs discrete-time analysis filters and continuous-time synthesis filters for digital-to-analog conversion.

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Revere, MA, United States of America

Scott R Velazquez