Mbit Wireless, Inc.

Keerthivasan Suresh

Krishnavelan Sivaraman

Karthik Thirukannan

Anandhavadivel Sepperumal

Akshayavarnikha Muthuraj

Kirubakaran Ponnurangam

The propagation channel in a wireless communication system may be characterized as a multipath fading model wherein the multiple delayed and attenuated versions of the transmitted signal are received. In the receiver's processing chain, the impairments introduced by this propagation channel may be equalized using the channel estimates. The channel estimation is mainly performed using the known reference signals by conventional methods. The estimation of delay spread profile may be crucial for high performance channel estimation. The conventional methods may be appropriate for high operating channel bandwidths. In the case of low channel bandwidth, limited number of reference signals may be available which may not be adequate for accurate delay spread estimation. A method and apparatus are disclosed that improve the delay spread estimation for low channel bandwidth scenarios.

Method and apparatus for delay spread estimation

Fading profile detection may be used in many wireless communication system receivers to perform improved channel estimation and decoding. Delay spread may be very high for some fading profiles and hence the coherence bandwidth may be very limited for these fading profiles. It may not be possible to reliably differentiate high delay spread fading profiles from low and mid delay spread fading profiles by the conventional delay spread estimation techniques. A method and apparatus are disclosed that can identify and differentiate high delay spread fading profiles from the low and mid delay spread fading profile to perform improved channel estimation and decoding of the received data.

Method and apparatus for fading profile detection

MMSE-IRC receiver may be used to suppress inter-cell interference for improving the cell-edge user throughput in cellular wireless communication systems. But MMSE-IRC performance is limited by estimation errors, namely, channel estimation error and covariance matrix estimation error. It is important to have an accurate covariance matrix estimation scheme, so that maximum gain from MMSE-IRC receiver may be achieved. In order to have accurate estimation, covariance matrix may be averaged across channel bandwidth in frequency domain. A method and apparatus are disclosed that adaptively determine the averaging bandwidth employed for covariance matrix estimation based on the detected delay spread and SNR. Based on the present disclosure, the throughput performance of MMSE-IRC receiver may be improved by adaptively using suitable sub-band length in frequency domain averaging of covariance matrix estimation.

Method and apparatus for adaptive covariance estimation

Low latency wireless communication applications require highly dynamic allocation of resources. Providing allocation information on a highly dynamic basis increases the overhead of control signaling for allocation. A technique known as blind decoding is used to reduce the control signaling overhead for allocation information. However, blind decoding may occasionally lead to invalid detection of allocation messages which in turn may lead to a number of problems such as wasted bandwidth, increased power consumption, reduced throughput, etc. A method and apparatus are disclosed that detect the invalid allocation messages by maintaining a record of previously received allocation messages and using it to check the validity of the newly received allocation messages.

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Chennai, India

Keerthivasan Suresh