Multiple band multiple input multiple output transceiver integrated circuit

A MIMO transceiver integrated circuit (IC) includes a plurality of multiple band direct conversion transmitter sections, a plurality of multiple band direct conversion receiver sections, and a local oscillation generation module. Each of the plurality of multiple band direct conversion transmitter sections includes a transmit baseband module and a multiple frequency band transmission module. Each of the plurality of multiple band direct conversion receiver sections includes a multiple frequency band reception module and a receiver baseband module. The local oscillation generation module is operably coupled to generate the first frequency band local oscillation when the multiple band MIMO transceiver IC is in a first mode and operably coupled to generate the second frequency band local oscillation when the multiple band MIMO transceiver IC is in a second mode.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to wireless communication systems and more particularly to multiple frequency band wireless communications.

2. Description of Related Art

For each wireless communication device to participate in wireless communications, it includes a built-in radio transceiver (i.e., receiver and transmitter) or is coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.). As is known, the transmitter includes a data modulation stage, one or more intermediate frequency stages, and a power amplifier. The data modulation stage converts raw data into baseband signals in accordance with a particular wireless communication standard. The one or more intermediate frequency stages mix the baseband signals with one or more local oscillations to produce RF signals. The power amplifier amplifies the RF signals prior to transmission via an antenna.

As is also known, the receiver is coupled to the antenna and includes a low noise amplifier, one or more intermediate frequency stages, a filtering stage, and a data recovery stage. The low noise amplifier receives inbound RF signals via the antenna and amplifies then. The one or more intermediate frequency stages mix the amplified RF signals with one or more local oscillations to convert the amplified RF signal into baseband signals or intermediate frequency (IF) signals. The filtering stage filters the baseband signals or the IF signals to attenuate unwanted out of band signals to produce filtered signals. The data recovery stage recovers raw data from the filtered signals in accordance with the particular wireless communication standard.

For a wireless transceiver to operate in accordance with a particular wireless communication protocol, it must be designed to receive and transmit radio frequency (RF) signals within a given carrier frequency band using a particular baseband encoding, modulation, and/or scrambling protocol. For instance, IEEE 802.11a prescribes a frequency bands of 5.15-5.25 GHz, 5.25-5.35 GHz, and 5.725-5.825 GHz, using a modulation scheme of binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), sixteen quadrature amplitude modulation (16-QAM), or sixty-four quadrature amplitude modulation (64-QAM) and convolutional coding having a coding rate of ½, ⅔, or ¾. As another example, IEEE 802.11b prescribes a frequency band of 2.400 to 2.483 GHz and modulates that wave using Direct Sequence Spread Spectrum (DSSS) or Frequency Hopping Spread Spectrum (FHSS). As yet another example, IEEE 802.11g prescribes a frequency band of 2.400 to 2.483 GHz using a modulation scheme of binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), sixteen quadrature amplitude modulation (16-QAM), or sixty-four quadrature amplitude modulation (64-QAM).

From the above examples, for a wireless transceiver to operate in accordance with IEEE 802.11a, it must be able to transmit and receive RF signals in one of the 5 GHz frequency bands, while, to operate in accordance with IEEE 802.11b, or g, the wireless transceiver must be able to transmit and receive RF signals in the 2.4 GHz frequency band. Because of the substantial difference in frequencies and the design of the transceiver, a wireless transceiver cannot effectively transmit RF signals in the different 5 GHz frequency bands and/or in the 2.4 GHz frequency band. Nevertheless, attempts have been made to integrated multiple frequency band transceivers as described in “A Single-Chip Digitally Calibrated 5.15-5.825 GHz 0.18 μm CMOS Transceiver for 802.11a Wireless LAN”, By Jason Vassiliou et, al. IEEE Journal of Solid-State circuits, Volume 38, No. 12, December 2003; and “A Single-Chip Dual-Band Tri-Mode CMOS Transceiver for IEEE 802.11a/b/g WLAN”, by Masoud Zargari, et. al., ISSCC 2004/Session 5/WLAN Transceivers/5.4.

Further advances in wireless communications include multiple input multiple output (MIMO) communications that utilizes multiple transmitters and multiple receivers for a single communication. Such MIMO communications theoretically provide a greater bandwidth than single input single output wireless communications. Currently, MIMO transceivers have been implemented using multiple integrated circuits and/or a super-heterodyne architecture.

While the prior art is making advance in wireless transceivers, there exists a need for an integrated multiple band direct conversion MIMO wireless communication transceiver.

BRIEF SUMMARY OF THE INVENTION

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a schematic block diagram of a communication system5that includes basic service set (BSS) areas7and9, an independent basic service set (IBSS)11, and a network hardware device15. Each of the BSS areas7and9include a base station and/or access point17,19and a plurality of wireless communication devices21-23,25-31. The IBSS11includes a plurality of wireless communication devices33-37. Each of the wireless communication devices21-37may be laptop host computers21and25, personal digital assistant hosts23and29, personal computer hosts31and33and/or cellular telephone hosts27and35.

The base stations or access points17and19are operably coupled to the network hardware15via local area network connections39and43. The network hardware15, which may be a router, switch, bridge, modem, system controller, et cetera provides a wide area network connection41for the communication system5. Each of the base stations or access points17,19has an associated antenna or antenna array to communicate with the wireless communication devices in its area. Typically, the wireless communication devices register with a particular base station or access point17,19to receive services from the communication system5. For direct connections (i.e., point-to-point communications) within IBSS11, wireless communication devices33-37communicate directly via an allocated channel.

Typically, base stations are used for cellular telephone systems and like-type systems, while access points are used for in-home or in-building wireless networks. Regardless of the particular type of communication system, each wireless communication device includes a built-in radio transceiver and/or is coupled to a radio transceiver to facilitate direct and/or in-direct wireless communications within the communication system5. The radio transceiver, as will be described in greater detail with reference toFIGS. 2-13.

FIG. 2is a schematic block diagram of a multiple band MIMO (multiple input multiple output) direct conversion radio frequency (RF) transceiver integrated circuit (IC) that includes a plurality of multiple band direct conversion transmit sections10-1through10-n, a plurality of multiple band direct conversion receiver sections12-1through12-n, and a local generation module22. Each of the multiple band direct conversion transmit sections10-1through10-nincludes a transmit baseband module14and a multiple frequency band transmission module16. Each of the multiple band direct conversion receiver sections12-1through12-nincludes a receiver baseband module18and a multiple frequency band reception module20.

In operation, each of the multiple band direct conversion transmit sections10-1through10-nmay receive an outbound baseband signal24-1through24-n. The outbound baseband signal24-1through24-nmay be in accordance with one or more wireless communication standards such as IEEE802.11a, b, g, n, and/or further extensions or variations thereof. In one embodiment, each of the multiple band direct conversion transmit sections10-1through10-nare tuned to convert outbound baseband signals24-1through24-ninto outbound RF signals with a 1stor 2ndRF carrier28-1through28-n. In addition, each of the multiple band direct conversion receiver sections12-1through12-nare tuned to converter inbound RF signals34-1through34-ninto processed inbound baseband signals38-1through38-n. In such an embodiment, the 1stRF carrier may be within the 2.4 GHz band (e.g., 2.400 GHz to 2.483) and the 2ndRF carrier maybe within one of the 5 GHz frequency bands (e.g., 5.15-5.25 GHz, 5.25-5.35 GHz, and 5.725-5.825 GHz).

For example, for a 4 by 4 MIMO wireless communication, the IC ofFIG. 2would include 4 multiple band direct conversion transmit sections10and 4 multiple band direct conversion receiver sections12. A MIMO baseband processor (not shown) converts a stream of outbound data into a plurality of outbound baseband signals24and converts a plurality of processed inbound baseband signals38into a stream of inbound data. Each of the multiple band direction conversion transmit sections10and12are tuned to convert their respective outbound baseband signals24into corresponding outbound RF signals having the 1stor the 2ndRF carrier28. Similarly, each of the multiple band direct conversion receiver sections12are tuned to convert their respective inbound RF signals having the first or second RF carrier34into corresponding processed inbound baseband signals38. The selection of the 1stor the 2ndRF carrier frequency maybe based on which RF carrier will provide a more efficient wireless communication (e.g., has less interference such that the data can be transmitted at a higher rate with less errors), a default protocol, user preference, capabilities of devices involved in the wireless communication, and/or system requirements.

As one of ordinary skill in the art will appreciate, the IC ofFIG. 2may include any number of multiple band direct conversion transmit sections10and any number of multiple band direct conversion receiver sections12. In addition, any number in any combination of the multiple band direct conversion transmit sections10and multiple band direct conversion receiver sections12may be active to facilitate a MIMO wireless communication. For example, if the IC includes M number of multiple band direct conversion transmit sections10and N number of multiple band direct conversion receiver sections12, where M may or may not equal N, the IC may support an M by N MIMO wireless communications. In addition, the IC may active less than M multiple band direct conversion transmit sections10and/or may active less than N multiple band direct conversion receiver sections12to support m by n MIMO wireless communications, where m represents the number of the M multiple band direct conversion transmit sections10that are activated and n represents the number of the N multiple band direct conversion receiver sections12that are activated.

As one of ordinary skill in the art will further appreciate, the IC may include one multiple band direct conversion transmit section10and one multiple band direction conversion receiver section121to provide multiple band direction conversion transceiver. In this instance, a baseband processing module (not shown) produces the outbound baseband signals24from outbound data and produces inbound data from the processed inbound baseband signals38in accordance with a wireless communication protocol (e.g., IEEE 802.11a, b, g). The multiple band direct conversion transmit section10converts the outbound baseband signals24in to outbound RF signals having the first or the second RF carrier frequency28, while the multiple band direct conversion receiver section12converts inbound RF signals having the first or the second RF carrier frequency34into the processed inbound baseband signals38.

Regardless of the numbers of the multiple band direct conversion transmit and receiver sections10and12contained on the IC, each of the multiple band direct conversion transmit sections10operate in a similar manner and each of the multiple band direct conversion receiver sections12operate in a similar manner. For instance, to facilitate the baseband to RF conversion within each of the multiple band direct conversion transmit sections10, the transmit baseband module14processes the outbound baseband signals24-x(where x represents 1 through n) to produce processed outbound baseband signals26. The processing includes one or more of filtering, analog-to-digital conversion, gain adjust and/or phase adjust of the outbound baseband signals24-x. Note that the outbound baseband signals24-xmay include an in-phase component and a quadrature component such that the processed outbound baseband signals26include a processed in-phase component and a processed quadrature component.

Within each of the multiple band direct conversion transmit sections10, the multiple frequency band transmission module16converts the processed outbound baseband signals26into outbound RF signals28-xbased on a 1stor 2ndlocal oscillation30, which is produced by local oscillation generation module22. In one embodiment, the 1stcarrier frequency and the first local oscillation30-1will correspond to a frequency within the 2.4 GHz band. Accordingly, the multiple frequency band transmission module16converts the processed outbound baseband signals26into outbound RF signals having a 2.4 GHz RF carrier frequency28-x. Alternatively, the RF carrier frequency and the second local oscillation30-2maybe within one of the 5 GHz frequency bands. In this instance, the LO generation module22generates a local oscillation within one of the 5 GHz bands such that the multiple frequency band transmission module16converts the processed outbound baseband signals26into the outbound RF signals with a 5 GHz RF carrier28-x.

Each of the multiple band direct conversion receiver sections12-xreceives inbound RF signals with the 1stor 2ndRF carrier34-xand, via the multiple frequency band reception module20, converts the inbound RF signal into inbound baseband signals36in accordance with the 1stor 2ndlocal oscillation30. For example, the inbound RF signals may have a carrier frequency in accordance with IEEE802.11a, or in accordance with IEEE802.11b or g. Depending on which wireless communication standard is supported, the LO generation module22generates the 1stlocal oscillation to have a frequency corresponding to the 1stRF carrier frequency (e.g., within the 2.4 GHz frequency band) or the 2ndlocal oscillation having a frequency corresponding to the 2ndRF carrier (e.g., within one of the 5 GHz frequency bands).

The receiver baseband module18converts the inbound baseband signals36into process inbound baseband signals38-x. The processing may include one or more of filtering, analog-to-digital conversion, gain adjust, phase adjust, and/or received signal strength measurements. The receiver baseband module18will be described in greater detail with reference toFIG. 12.

FIG. 3is a diagram of the frequency bands that may be used in accordance with the present invention. As shown, a 1stfrequency band40is separate from a 2ndfrequency band42. In one embodiment, the 1stfrequency band40may correspond with a 2.4 GHz frequency band (e.g., 2.400 GHz to 2.483 GHz) and the 2ndfrequency band42may correspond to one or more 5 GHz frequency bands (e.g., 5.15-5.25 GHz, 5.25-5.35 GHz, and 5.725-5.825 GHz).

Within the 1stfrequency band40, a 1stRF carrier frequency44may be positioned to correspond with a particular channel within the 1stfrequency band40, or may correspond to the center of the frequency band40. Similarly, a 2ndRF carrier45is shown within the 2ndfrequency band42. The 2ndRF carrier frequency45may correspond to a particular channel within the 2ndfrequency band42and/or the center frequency of the frequency band. Note that the 1stand/or 2ndfrequency band40and42may include a plurality of frequency bands, for example the 2ndfrequency band may include a frequency band from 5.15 GHz to 5.25 GHz, from 5.25 GHz to 5.35 GHz, and from 5.725 GHz to 5.825 GHz. Further note that the 1stfrequency band40may be one of the 5.15 GHz to 5.25 GHz, from 5.25 GHz to 5.35 GHz, and from 5.725 GHz to 5.825 GHz frequency bands and the 2ndfrequency band42may be another one of the 5.15 GHz to 5.25 GHz, from 5.25 GHz to 5.35 GHz, and from 5.725 GHz to 5.825 GHz frequency bands. Still further note that the 1stand 2ndfrequency bands40and42may include different frequency bands than the ones listed in the preceding examples as may be allocated for wireless communications by a controlling governmental entity.

FIG. 4is a schematic block diagram of an embodiment of a multiple frequency band transmission module16that includes a 1stfrequency band transmission module50, a 2ndfrequency band transmission module52and a transmitter multiplexer54. In operation, the process outbound baseband signals26are provided to the transmit multiplexer54. Based on a 1stor 2ndmode signal32, the multiplexer54provides the processed outbound baseband signals26to either the 1stfrequency baseband transmission module50or to the 2ndfrequency baseband transmission module52. In one embodiment, the 1stmode of mode signal32corresponds to transmitting the outbound RF signals having an RF carrier frequency within a 1stfrequency band42and the 2ndmode of the mode signal32corresponds to transmitting the outbound RF signals having an RF carrier frequency within the 2ndfrequency band42.

Accordingly, for the 1stmode of the mode signal32, the transmitter multiplexer54provides the processed outbound baseband signals26to the 1stfrequency baseband transmission module50. The 1stfrequency band transmission module50, which will be described in greater detail with reference toFIG. 5, converts the processed outbound baseband signals26into outbound RF signals with the 1stRF carrier28ain accordance with the 1stlocal oscillation30-1. In one embodiment, the 1stRF carrier corresponds to a frequency within the 1stfrequency band40.

For the 2ndmode of the mode signal32, the transmitter multiplexer54provides the processed outbound baseband signals26to the 2ndfrequency baseband transmission module52. The 2ndfrequency baseband transmission module52, which will be described in greater detail with reference toFIG. 5, converts the processed outbound baseband signals26into outbound RF signals with the 2ndRF carrier28-bin accordance with the 2ndlocal oscillation30-2.

As one of average skill in the art will appreciate, the processed outbound baseband signals26may have an in-phase component and a quadrature component. Accordingly, each of the 1stand 2ndfrequency band transmission modules50and52produces the outbound RF signals28aand28bfrom I and Q components of the processed outbound baseband signals26in accordance with I and Q components of the 1stor 2ndlocal oscillations30-1or30-2.

FIG. 5is a schematic block diagram of an embodiment of the 1stor 2ndfrequency band transmission module50or52that includes a mixing module60and a power amplifier driver74. The mixing module60includes a 1stmixer62, a 2ndmixer64, a 90° phase shift module66and a summation module68. The 1stmixer62mixes an I component70of the processed outbound baseband signals26with an in-phase component of the local oscillation30to produce a 1stmixed signal. The 2ndmixer64mixes a quadrature component72of the processed outbound baseband signals26with a 90° phase shifted representation of the local oscillation30, which corresponds to a Q component, to produce a 2ndmixed signal. The summing module68sums the 1stand 2ndmixed signals to produce a summed mixed signal. The power amplifier driver74amplifies the summed mixed signals to produce the outbound RF signals28aor28b.

FIG. 6is a schematic block diagram of an embodiment of a multiple frequency band reception module20that includes a 1stfrequency band reception module80, a 2ndfrequency band reception module82and a receiver multiplexer84. The 1stfrequency band reception module80converts inbound RF signals having a 1stcarrier frequency34ainto baseband signals in accordance with the 1stlocal oscillation30-1. The 2ndfrequency baseband module82converts inbound RF signals with the 2ndRF carrier34-binto baseband signals in accordance with the 2ndlocal oscillation30-2. In one embodiment, the 1stRF carrier and 1stlocal oscillation30-1are in the 2.4 GHz frequency band and the 2ndRF carrier and 2ndlocal oscillation30-2are in one of the 5 GHz frequency bands.

The receiver multiplexer84is operably coupled to output the baseband signals36from the 1stor 2ndfrequency band reception modules80or82based on the 1stor 2ndmode signal32to produce the inbound baseband signal36. In one embodiment, the 1stmode of mode signal32corresponds to receiving the inbound RF signals having an RF carrier frequency within a 1stfrequency band42and the 2ndmode of the mode signal32corresponds to receiving the inbound RF signals having an RF carrier frequency within the 2ndfrequency band42.

As one of average skill in the art will appreciate, the inbound baseband signals36may have an in-phase component and a quadrature component. Accordingly, each of the 1stand 2ndfrequency band transmission modules80and82produces I and Q components of the inbound baseband signals36from the inbound RF signals34A or34B in accordance with I and Q components of the 1stor 2ndlocal oscillations30-1or30-2.

FIG. 7is a schematic block diagram of an embodiment of the 1stand/or 2ndfrequency band reception modules80or82. The module80or82includes a mixing module92and a low noise amplifier90. The mixing module92includes a 1stmixer94, a 2ndmixer96, and a 90° phase shift module98.

The low noise amplifier90receives the inbound RF signals having the 1stor 2ndcarrier frequency34-aor34-band amplifies it to produce an amplified inbound RF signal102. The mixing module92receives the amplified inbound signal102via the 1stmixing module94. The 1stmixing module94mixes the amplified inbound RF signal102with an in-phase component of the local oscillation30to produce an I component104of the inbound baseband signal36.

The 90° phase shift module100produces a phase shifted representation of the amplified inbound RF signal102. The second mixer96mixes the 90° phase shifted representation of the amplified inbound RF signal102with a 90° phase shifted representation of the local oscillation to produce a Q component106of the inbound baseband signals36.

FIG. 8is a schematic block diagram of another embodiment of the multiple frequency baseband transmit module16. In this embodiment, module16includes a mixing module110, a 1stmultiplexer112, a 2ndmultiplexer144, a 1stpower amplifier driver module116and a 2ndpower amplifier driver module118. The mixing module110receives the processed outbound baseband signals26and the 1stor 2ndmode control signal32. Multiplexer112receives the 1stand 2ndlocal oscillations30-1and30-2and the 1stor 2ndmode control signal32. When the integrated circuit is in a 1stmode, the mixing module110is tuned to mix the outbound baseband signals26with the 1stlocal oscillation30-1. When the integrated circuit is in the 2ndmode, the mixing module110is tuned to mix the 2ndlocal oscillation30-2with the processed outbound baseband signals26. The tuning of mixing module110includes, but is not limited to, adjusting the inductors within the mixers of the mixing module110. For example, mixing module110may be similar to mixing module60ofFIG. 5where mixers62and64are adjustable based on the corresponding mode signal32. In addition, the 90° phase shift module of66, if used within mixing module110, may also be tuned to the particular local oscillation being used.

The multiplexer144provides the output of mixing module110to either the 1stpower amplifier driver116or the 2ndpower amplifier driver118based on the mode signal32. The 1stpower amplifier driver116is tuned to amplify signals having the 1stcarrier frequency to produce the RF outbound signals28awhile the 2ndpower amplifier driver module118is tuned to amplify the outbound RF signals having the 2ndcarrier frequency28b.

As one of average skill in the art will appreciate, the processed outbound baseband signals26may have an in-phase component and a quadrature component. Accordingly, the multiple frequency band transmission module16produces the outbound RF signals28aand28bfrom I and Q components of the processed outbound baseband signals26in accordance with I and Q components of the 1stor 2ndlocal oscillations30-1or30-2.

FIG. 9is another embodiment of the multiple frequency band transmission module16that includes the mixing module110and an adjustable power amplifier driver module120. In this embodiment, mixing module110and multiplexer112operate as previously described with reference toFIG. 8. In this embodiment, the adjustable power amplifier driver120is adjusted based on the 1stor 2ndmode control signal32to produce the outbound RF signals having the 1stor 2ndcarrier frequency28aor28b.

As one of average skill in the art will appreciate, the processed outbound baseband signals26may have an in-phase component and a quadrature component. Accordingly, the multiple frequency band transmission module16produces the outbound RF signals28aand28bfrom I and Q components of the processed outbound baseband signals26in accordance with I and Q components of the 1stor 2ndlocal oscillations30-1or30-2.

FIG. 10is a schematic block diagram of another embodiment of the multiple frequency band reception module20. In this embodiment, the module20includes a 1stlow noise amplifier130, a 2ndlow noise amplifier132, a multiplexer134, a mixing module136and a multiplexer138. In a 1stmode of operation, the 1stlow noise amplifier130receives inbound RF signals having a 1stcarrier frequency34aand amplifies them to produce inbound amplified RF signals140. Multiplexer134, in accordance with a first mode of the 1stor 2ndmode control signal32, passes the 1stamplified RF signals140to the mixing module136. In addition, multiplexer138provides the 1stlocal oscillation30-1to the mixing module136in accordance with the first mode of the 1stor 2ndmode control signal32. The mixing module136mixes the 1stamplified RF signals140with the 1stlocal oscillation30-1to produce the inbound baseband signal36. In this embodiment, the mixing module136may be tuned in accordance with the first mode of the 1stor 2ndmode signal32.

In a 2ndmode of operation, the 2ndlow noise amplifier132receives the inbound RF signals having the 2ndcarrier frequency34band amplifies them to produce 2ndamplified RF signals142. In accordance with the second mode of the 1stor 2ndmode control signal32, multiplexer134provides the 2ndamplified RF signals142to the mixing module136and multiplexer138provides the 2ndlocal oscillation32to mixing module136. The mixing module136is tuned in accordance with the 1stor 2ndcontrol signal32and mixes the 2ndamplified RF signal142with the 2ndlocal oscillation30-2to produce the inbound baseband signals36.

As one of ordinary skill in the art will appreciate, the mixing module136may include similar components to mixing module92ofFIG. 7where the 1stmixing module and 2ndmixing module94and96would be adjustable based on the corresponding frequencies of operation. In addition, the 1stand 2nd90° phase shift modules98and100may also be adjustable based on the particular frequencies of operation. As one of average skill in the art will further appreciate, the inbound baseband signals36may have an in-phase component and a quadrature component. Accordingly, multiple frequency band reception module20produces I and Q components of the inbound baseband signals36from the inbound RF signals34A or34B in accordance with I and Q components of the 1stor 2ndlocal oscillations30-1or30-2.

FIG. 11is a schematic block diagram of another embodiment of the multiple frequency band reception module20. In this embodiment, module20includes the mixing module136, the multiplexer138, and adjustable low noise amplifier150. The mixing module136and multiplexer138operate as previously described with reference toFIG. 10.

The adjustable LNA150, in accordance with the 1stor 2ndmode control signal32, receives the inbound RF signal having the 1stor 2ndcarrier frequency34aor34band produces there from amplified inbound RF signals. When the control signal32indicates the 1stmode of operation, the low noise amplifier150is tuned to the frequency corresponding to the 1stcarrier frequency. In addition, the adjustable LNA150receives the inbound RF signals having the 1stcarrier frequency34to produce the amplified inbound RF signals.

In the 2ndmode, the adjustable, or band tunable, LNA150is adjusted to frequencies corresponding to the 2ndRF carrier frequency such that it may receive and amplify the inbound RF signals having the 2ndcarrier frequency34b. As one of average skill in the art will appreciate, the inbound baseband signals36may have an in-phase component and a quadrature component. Accordingly, multiple frequency band reception module20produces I and Q components of the inbound baseband signals36from the inbound RF signals34A or34B in accordance with I and Q components of the 1stor 2ndlocal oscillations30-1or30-2.

FIG. 12is a schematic block diagram of an embodiment of the receiver baseband module18. In this embodiment, module18includes a 1stvariable gain amplifier module160, a low pass filter module162, a 2ndvariable gain module164and a driver module166. Each of the variable gain modules160and164has its gain set based on the magnitude of the inbound signals to produce a desired level for the process inbound baseband signal38. In addition, each of the outputs of modules160,162and164may be used for RSSI (received signal strength indication) measurements.

FIG. 13is a schematic block diagram of a 2×2 MIMO transceiver integrated circuit. The MIMO transceiver includes a baseband processing module178, a plurality of transmit/receive switches170-176, a pair of multiple band direct conversion transmit sections10and a pair of multiple band direct conversion receive sections12. The multiple band direct conversion transmit section includes the 1stand 2ndfrequency band transmission modules50and52, transmit multiplexer54and transmit baseband module14. Each of the multiple band direct conversion receiver sections include the 1stand 2ndfrequency band reception modules80and82, the receiver multiplexer84and the receiver baseband module18.

In operation, when the 2×2 MIMO transceiver is to transmit data, the baseband processing module178processes outbound data and provides a portion of it to the baseband processing modules14. Each of the baseband processing modules14processes their portion of the output data to produce the processed outbound baseband signals26, which are provided to the corresponding multiplexers54. When the device is in the 1stmode, the 1stfrequency band transmit sections50are activated to convert the corresponding processed outbound baseband signals26into the outbound RF signals having the first RF carrier frequency, which are provided to transmit/receive switch170and174, respectively, for a MIMO transmission. When the device is in the 2ndmode, the 2ndfrequency band transmissions modules52are active to convert the processed outbound baseband signals into the RF signals having the second RF carrier frequency, which are provided to the RF signals to transmit receive sections172and176for a MIMO transmission.

For reception of a MIMO signal, where the device is in a 1stmode, the 1stfrequency reception modules80receive the inbound RF signals having the first RF carrier frequency via transmit/receive switches172and174. The 1stfrequency band reception modules80convert the inbound RF signals into the inbound baseband signals and provide them to multiplexers84. Multiplexers84provide the inbound baseband signals to the receiver baseband processing modules18, which produce the processed inbound baseband signals. The receiver baseband processing modules18provide the processed inbound baseband signals to the baseband processing module178, which produces the inbound data from the two streams of processed inbound baseband signals.

In the 2ndmode of operation, the 2ndfrequency band receiver modules82receive the inbound RF signals having the second RF carrier frequency via transmit/receive switches170and176, respectfully. The 2ndfrequency band reception modules82convert the inbound RF signals into the inbound baseband signals and provide them to multiplexers84. Multiplexers84provides the inbound baseband signals to the receiver baseband processing modules18, which produce the processed inbound baseband signals. The receiver baseband processing modules18provide the processed inbound baseband signals to the baseband processing module178, which produces the inbound data from the two streams of processed inbound baseband signals.

As one of ordinary skill in the art will appreciate, the RF transceiver ofFIG. 13, which includes modules14,18,54,84,80,82,50and52, may be implemented on one integrated circuit, may be implemented on two integrated circuits, or may be included on four integrated circuits as indicated by the dashed lines.

The preceding discussion has presented a multi-band direct conversion transceiver, receiver and/or transmitter. As one of average skill in the art will appreciate, other embodiments may be derived from the teachings of the present invention without deviating from the scope of the claims. For example, the RF receiver sections and transmit sections may have a direct conversion topology or a super-heterodyne topology.