METHOD AND APPARATUS FOR MULTIPLE RADIO RECEIVE CHAINS IN WIRELESS COMMUNICATION SYSTEMS

• US 20120108284A1
• Filed: 01/09/2012
• Published: 05/03/2012
• Est. Priority Date: 03/09/2007
• Status: Active Grant

• Current Assignee: Mbit Wireless Inc.
• Original Assignee: Arumugam Govindaswamy, Bhaskar Patel, Sarath Babu Govindarajulu
• Inventors: Patel, Bhaskar, Govindswamy, Arumugam, Govindarajulu, Sarath Babu
• Granted Patent: US 8,260,231 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00

Abstract

The present invention provides architectures and methods which use multiple radio receive chains in mobile devices to boost performance of the mobile devices. While a first set of the receive chains are assigned to a serving base station, another set of receive chains are dynamically allocated to neighbor base stations and/or to the serving base station depending upon present or expected system conditions and timing. A first synthesizer is configured to provide signals to the first and second set of receive chains. Other synthesizers are also configured to provide signals to the second set of receive chains. Thus, depending on the mode of operation, the second set of receive chains utilizes signals from a given synthesizer as needed. A priori data may be used to allocate specific receive chains to the serving base station, neighboring base stations or both. Unused synthesizers may be turned off to conserve power.

Claims

1. A method of allocating receive chains among base stations in a wireless network, the method comprising:

determining a total number of receive chains R_T available in a receiver subsystem of a wireless communication device;

determining a total number of synthesizers S_T in the receiver subsystem;

determining a number of receive chains N_S, out of the total number of receive chains R_T, that are needed to receive a signal from a currently serving base station; and

comparing R_T against N_S, wherein;

if R_T is not greater than N_S, then tuning the R_T receive chains to a channel of the currently serving base station, and

if R_T is greater than N_S, then;

identifying, from the total number of receive chains R_T, which receive chains N_S are to process signals from the currently serving base station;

tuning the receive chains N_S to the channel of the currently serving base station; and

tuning a remaining number of the total number of receive chains R_T to different channels to make measurements of signals of at least some of the other base stations.

2. The method of claim 1, further comprising:

determining a priori information about the wireless network;

wherein identifying the receive chains N_S to process the signals from the currently serving base station is based upon the a priori information.

3. The method of claim 2, wherein the a priori information includes at least one of signal to noise ratio and carrier to interference and noise ratio for each of the total number of receive chains R_T.

4. The method of claim 2, wherein:

if R_T is not greater than N_S, then the method further includes turning off any synthesizers not tuned to the channel of the currently serving base station; and

if R_T is greater than N_S, then the method further comprises turning off any unused synthesizers out of the total number of synthesizers S_T.

5. The method of claim 1, wherein determining the number of receive chains N_S that are needed to receive the signal from the currently serving base station is based on at least one of a signal condition, a broadcast message received by the wireless communication device and a unicast control message received by the wireless communication device.

6. The method of claim 1, wherein determining the number of receive chains N_S that are needed to receive the signal from the currently serving base station is performed repeatedly in multiple decision periods over a given unit of time.

7. The method of claim 6, wherein values determined in each decision period are stored together as an array.

8. The method of claim 1, wherein a given receive chain is tuned to the channel of the currently serving base station or to one of the different channels by operatively coupling the given receive chain to a corresponding synthesizer and selecting an appropriate frequency of interest of the corresponding synthesizer, and wherein the frequency of interest is selectable.