Quantized detection in uplink MIMO with oversampling

• US 10,447,504 B1
• Filed: 05/16/2018
• Issued: 10/15/2019
• Est. Priority Date: 05/16/2018
• Status: Active Grant

• Current Assignee: Orta Dogu Teknik Universitesi
• Original Assignee: Orta Dogu Teknik Universitesi
• Inventors: Yilmaz, Ali Ozgur, Ucuncu, Ali Bulut
• Primary Examiner(s): Liu, Shuwang
• Assistant Examiner(s): Mckie, Gina M
• Application Number:
  US15/980,895
• Time in Patent Office: 517 Days
• CPC Class Codes: H03D 3/006 by sampling the oscillations and further processing the samples, e.g. by computing techniques H03D3/007 takes precedence
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/0256 Channel estimation using minimum mean square error criteria
• CPC Class Codes: H04L 25/03038 with a non-recursive structure H04L25/03031 takes precedence

Abstract

The invention relates to a quantized detection in uplink mimo with oversampling that is a temporal oversampling in quantized uplink MIMO systems.

Claims

1. A method of a quantized detection in an uplink mimo with oversampling which takes samples faster than a symbol rate for the uplink MIMO with a 1-bit ADC, the method comprising the steps of:

obtaining a relation between transmitted data symbols x and a quantized temporally oversampled observation vector r in a simple form y=Hx+n, by deriving an oversampled channel matrix H, a detector providing an estimate for the transmitted data symbols x based on the quantized temporally oversampled observation vector r, the oversampled channel matrix H and a derived simple relation between the oversampled channel matrix H and the quantized temporally oversampled observation vector r=Q(Hx+n);

wherein Q(Hx+n) is a quantizer function mapping an input of a quantizer to discrete levels, and n is a noise vector; and

wherein the detector utilizes a temporal oversampling in the uplink quantized MIMO method.

2. The method of claim 1, wherein the detector is a zero-forcing (ZF) detector.

3. The method of claim 1, wherein the detector is a block sequential linear minimum mean squared estimate BS-LMMSE detector.

4. The method of claim 1, wherein the detector is characterized by G(r,H), based on the derived simple linear relation r=Q(Hx+n) and the derived oversampled channel matrix H, for which receiver estimates a transmit vector x.

5. The method of claim 4, wherein the detector is a linear minimum mean squared estimate or a best-linear unbiased estimator BLUE or a factor-graph based receiver.

6. The method of claim 1, wherein the detector utilizing the temporal oversampling in the uplink quantized MIMO method G(r,H) reduces a necessary number of receiver antennas to maintain a predetermined error rate.

7. The method of claim 1, wherein the detector takes into account the quantized temporally oversampled observation vector r and the derived oversampled channel matrix H to provide up to a 4 dB signal-to-noise ratio (SNR) advantage compared to SR sampling in terms of an error rate performance of a 1-bit quantized uplink MIMO for narrowband fading channel scenario.

8. The method of claim 1, wherein the detector takes into account the quantized temporally oversampled observation vector r and the derived oversampled channel matrix H to provide up to a 9 dB signal-to-noise ratio (SNR) advantage compared to SR sampling in terms of an error rate performance of a 1-bit quantized uplink MIMO for wideband fading channel scenario.

9. The method of claim 1, wherein the detector is ZF and BS-LMMSE (Lⁿ=6, P=M/8) detectors, and the detectors reduce a necessary number of antennas to satisfy a SER of 10⁻

3 by 70% for perfect CSI when SNR=−

12 dB and by 60% for an imperfect CSI case when SNR=−

7 dB by temporal oversampling.

10. The method of claim 1, wherein the detector provides up to a 9 dB SNR advantage with up to 70% decrease in the number of receiver antennas.

11. A quantized uplink MIMO system using the method of claim 1.