Parameter estimator for a multiuser detection receiver
OwnerMatthew A. Taylor, Joshua D. Niedzwiecki +1inventors
InventorsMatthew A. Taylor, Joshua D. Niedzwiecki, Robert B. MacLeod
Life of this patent
Estimating the term…
Abstract
A Parameter Estimator for accurately estimating signature responses of multiple co-channel interfering digital transmission signals. The Parameter Estimator is used in a Multiuser Detection (MUD) Receiver to significantly reduce the error rate. The Parameter Estimator comprises a plurality of software components, including a Signature Waveform Estimator, Training Sequence Locator, Noise Estimator, Active Users Tester, Initial Transformation Matrix Builder, a Transformation Matrix Rebuilder, and a Transformation Matrix Selector, and generates an estimated noise power, a training sequence index and estimated signature waveforms.
Claims14
A parameter estimator of a multiuser detection receiver comprising:
- means for estimating a training sequence location index (τTS) in each frame of a received baseband signal;
- means for calculating an estimate of an average noise power ({circumflex over (σ)}(p)2) in said received baseband signal in accordance with said training sequence location index (τTS) input;
- means for estimating signature waveforms (sK(n,p)) unique to each user in said received baseband signal in accordance with said training sequence location index (τTS) input and said transformation matrix (Tr) input;
- means, coupled to an output of said estimate of an average noise power calculating means and to an output of said signature waveforms estimating means, for determining the number of active users;
- and
- means, coupled to said means for determining the number of active users and to prestored known training sequences for each user, for generating said transformation matrix (Tr) to send to said signature waveform estimating means.
A multiuser communication system comprising:
- a plurality of user transmitters transmitting co-channel interfering signals;
- a receiver having means for receiving a composite waveform signal from said plurality of user transmitters;
- said receiver further comprises means for converting said received composite waveform signal to a received baseband signal;
- means, coupled to said received baseband signal, for generating estimated signature waveforms of each user (k) for each diversity port (p) by using said received baseband signal from each diversity port in accordance with known training sequences of each of said plurality of user transmitters;
- means for storing said known training sequence of each of said plurality of user transmitters;
- and
- means for demodulating said received baseband signal in accordance with information received from said estimated signature waveform generating means to generate symbols for each of said plurality of user transmitters.
A method of estimating parameters of a received baseband signal in a multiuser detection receiver comprising the steps of:
- estimating a training sequence location index in each frame of said received baseband signal;
- estimating signature waveforms unique to each user in each received baseband signal in response to said training sequence location index and a transformation matrix;
- determining a number of active users with means coupled to outputs of said average noise power and an estimation of said signature waveforms unique to each user in said receive baseband signal;
- and
- generating said transformation matrix with first means coupled to outputs of said number of active users determining means and second means coupled to outputs of prestored known training sequence.
The method as recited in Clam 13 wherein said step of generating said transformation matrix comprises the steps of:
- building an initial transformation matrix in response to said prestored known training sequences for each user for use during a first iteration of a signature estimation loop;
- rebuilding said transformation matrix in response to an output from said number of active users determining means for use during subsequent iterations of said signature estimation loop;
- and
- selecting a transformation matrix from said initial transformation matrix iteration or said rebuilt transformation matrix iterations of said signature estimation loop, to feed to said means for estimating signature waveforms unique to each user.
Dependencies are inferred from the claim text.